Systems and methods for registration of location sensors

ABSTRACT

Provided are systems and methods for registration of location sensors. In one aspect, a system includes an instrument and a processor configured to provide a first set of commands to drive the instrument along a first branch of the luminal network, the first branch being outside a path to a target within a model. The processor is also configured to track a set of one or more registration parameters during the driving of the instrument along the first branch and determine that the set of registration parameters satisfy a registration criterion. The processor is further configured to determine a registration between a location sensor coordinate system and a model coordinate system based on location data received from a set of location sensors during the driving of the instrument along the first branch and a second branch.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a continuation of U.S. application Ser. No.16/735,218, filed Jan. 6, 2020, which is a continuation of U.S.application Ser. No. 16/365,386, filed Mar. 26, 2019, which claims thebenefit of U.S. Provisional Application No. 62/649,513, filed Mar. 28,2018, each of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The systems and methods disclosed herein are directed to systems andmethods for registration of location sensors, and more particularly toregistering a location sensor coordinate system to another coordinatesystem.

BACKGROUND

Medical procedures such as endoscopy (e.g., bronchoscopy) may involvethe insertion of a medical tool into a patient's luminal network (e.g.,airways) for diagnostic and/or therapeutic purposes. Surgical roboticsystems may be used to control the insertion and/or manipulation of themedical tool during a medical procedure. The surgical robotic system maycomprise at least one robotic arm including a manipulator assembly whichmay be used to control the positioning of the medical tool prior to andduring the medical procedure. The surgical robotic system may furthercomprise location sensor(s) configured to generate location dataindicative of a position of the distal end of the medical tool withrespect to a location sensor coordinate system.

The surgical robotic system may further utilize a model of a luminalnetwork of a patient, which may be defined with respect to a modelcoordinate system. The location sensor coordinate system may not beregistered to the model coordinate system, and thus the system mayperform a process to achieve registration between the location sensorcoordinate system and the model coordinate system such that locationdata received from the location sensor(s) can be used to determine theposition of the distal end of the medical tool with respect to themodel.

SUMMARY

The systems, methods and devices of this disclosure each have severalinnovative aspects, no single one of which is solely responsible for thedesirable attributes disclosed herein.

In one aspect, there is provided a system, comprising: an instrumentcomprising a set of one or more location sensors, the set of locationsensors configured to generate location data indicative of a position ofthe set of location sensors in a location sensor coordinate system; aset of instrument manipulators configured to control movement of thedistal end of the instrument; a set of processors; and at least onecomputer-readable memory in communication with the set of processors andhaving stored thereon a model of a luminal network of a patient, themodel comprising a target within a model coordinate system and a path tothe target. The memory may further have stored thereoncomputer-executable instructions to cause the set of processors to:provide a first set of commands to the set of instrument manipulators todrive the instrument along a first branch of the luminal network, thefirst branch being outside the path to the target, track a set of one ormore registration parameters during the driving of the instrument alongthe first branch; determine that the set of registration parameterssatisfy a registration criterion, provide a second set of commands tothe set of instrument manipulators to return the instrument back to thepath and to drive the instrument along a second branch, the secondbranch being part of the path to the target; and determine aregistration between the location sensor coordinate system and the modelcoordinate system based on the location data received from the set oflocation sensors during the driving of the instrument along the firstbranch and the second branch.

In another aspect, there is provided a non-transitory computer readablestorage medium having stored thereon instructions that, when executed,cause at least one computing device to: provide a first set of commandsto a set of instrument manipulators to drive an instrument along a firstbranch of a luminal network, the instrument comprising a set of one ormore location sensors, the set of location sensors configured togenerate location data indicative of a position of the set of locationsensors in a location sensor coordinate system, the set of instrumentmanipulators configured to control movement of the distal end of theinstrument, a memory having stored thereon a model of a luminal networkof a patient, the model comprising a target within a model coordinatesystem and a path to the target, the first branch being outside the pathto the target; track a set of one or more registration parameters duringthe driving of the instrument along the first branch; determine that theset of registration parameters satisfy a registration criterion; providea second set of commands to the set of instrument manipulators to returnthe instrument back to the path and to drive the instrument along asecond branch, the second branch being part of the path to the target;and determine a registration between the location sensor coordinatesystem and the model coordinate system based on the location datareceived from the set of location sensors during the driving of theinstrument along the first branch and the second branch.

In yet another aspect, there is provided a method of registering a setof one or more location sensors, comprising: providing a first set ofcommands to a set of instrument manipulators to drive an instrumentalong a first branch of a luminal network, the instrument comprising theset of location sensors, the set of location sensors configured togenerate location data indicative of a position of the set of locationsensors in a location sensor coordinate system, the set of instrumentmanipulators configured to control movement of the distal end of theinstrument, a memory having stored thereon a model of a luminal networkof a patient, the model comprising a target within a model coordinatesystem and a path to the target, the first branch being outside the pathto the target; tracking a set of one or more registration parametersduring the driving of the instrument along the first branch; determiningthat the set of registration parameters satisfy a registrationcriterion, providing a second set of commands to the set of instrumentmanipulators to return the instrument back to the path and to drive theinstrument along a second branch, the second branch being part of thepath to the target; and determining a registration between the locationsensor coordinate system and the model coordinate system based on thelocation data received from the set of location sensors during thedriving of the instrument along the first branch and the second branch.

In still yet another aspect, there is provided a system comprising a setof one or more processors and at least one computer-readable memory incommunication with the set of processors and having stored thereon amodel of a luminal network of a patient, the model comprising a targetwithin a model coordinate system and a path to the target, the memoryfurther having stored thereon computer-executable instructions to causethe set of processors to: provide instructions to display the luminalnetwork via a display device, receive an indication of a location of atarget within the model coordinate system; identify a first branch and asecond branch in the luminal network, the first branch being outside thepath to the target, the second branch being a part of the path to thetarget, generate a set of instructions for driving the distal end of theinstrument along the first branch, back to the path from the firstbranch, and along the second branch, wherein location data received froma set of one or more locations sensors during the driving of theinstrument according to the instructions facilitates a registrationbetween the a location coordinate system of the location data and themodel coordinate system; and determine a registration criterion for oneor more registration parameters tracked during the driving of theinstrument along the first branch.

In yet another aspect there is provided a non-transitory computerreadable storage medium having stored thereon instructions that, whenexecuted, cause at least one computing device to: provide instructionsto display a luminal network via a display device, the luminal networkbeing stored on the non-transitory computer readable storage medium, andthe model comprising a target within a model coordinate system and apath to the target; receive an indication of a location of a targetwithin the model coordinate system; identify a first branch and a secondbranch in the luminal network, the first branch being outside the pathto the target, the second branch being a part of the path to the target;generate a set of instructions for driving the distal end of theinstrument along the first branch, back to the path from the firstbranch, and along the second branch, wherein location data received froma set of one or more locations sensors during the driving of theinstrument according to the instructions facilitates a registrationbetween the a location coordinate system of the location data and themodel coordinate system; and determine a registration criterion for oneor more registration parameters tracked during the driving of theinstrument along the first branch.

In another aspect, there is provided a method of pre-operative planning,comprising: providing instructions to display a luminal network via adisplay device, the luminal network being stored on the non-transitorycomputer readable storage medium, and the model comprising a targetwithin a model coordinate system and a path to the target; receiving anindication of a location of a target within the model coordinate system;identifying a first branch and a second branch in the luminal network,the first branch being outside the path to the target, the second branchbeing a part of the path to the target; generating a set of instructionsfor driving the distal end of the instrument along the first branch,back to the path from the first branch, and along the second branch,wherein location data received from a set of one or more locationssensors during the driving of the instrument according to theinstructions facilitates a registration between the a locationcoordinate system of the location data and the model coordinate system;and determining a registration criterion for one or more registrationparameters tracked during the driving of the instrument along the firstbranch.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosed aspects will hereinafter be described in conjunction withthe appended drawings, provided to illustrate and not to limit thedisclosed aspects, wherein like designations denote like elements.

FIG. 1 illustrates an embodiment of a cart-based robotic system arrangedfor diagnostic and/or therapeutic bronchoscopy procedure(s).

FIG. 2 depicts further aspects of the robotic system of FIG. 1 .

FIG. 3 illustrates an embodiment of the robotic system of FIG. 1arranged for ureteroscopy.

FIG. 4 illustrates an embodiment of the robotic system of FIG. 1arranged for a vascular procedure.

FIG. 5 illustrates an embodiment of a table-based robotic systemarranged for a bronchoscopy procedure.

FIG. 6 provides an alternative view of the robotic system of FIG. 5 .

FIG. 7 illustrates an example system configured to stow robotic arm(s).

FIG. 8 illustrates an embodiment of a table-based robotic systemconfigured for a ureteroscopy procedure.

FIG. 9 illustrates an embodiment of a table-based robotic systemconfigured for a laparoscopic procedure.

FIG. 10 illustrates an embodiment of the table-based robotic system ofFIGS. 5-9 with pitch or tilt adjustment.

FIG. 11 provides a detailed illustration of the interface between thetable and the column of the table-based robotic system of FIGS. 5-10 .

FIG. 12 illustrates an exemplary instrument driver.

FIG. 13 illustrates an exemplary medical instrument with a pairedinstrument driver.

FIG. 14 illustrates an alternative design for an instrument driver andinstrument where the axes of the drive units are parallel to the axis ofthe elongated shaft of the instrument.

FIG. 15 depicts a block diagram illustrating a localization system thatestimates a location of one or more elements of the robotic systems ofFIGS. 1-10 , such as the location of the instrument of FIGS. 13 and 14 ,in accordance to an example embodiment.

FIG. 16A illustrates an example operating environment implementing oneor more aspects of the disclosed navigation systems and techniques.

FIG. 16B illustrates an example luminal network that can be navigated inthe operating environment of FIG. 16A.

FIG. 16C illustrates an example robotic arm of a robotic system forguiding instrument movement in through the luminal network of FIG. 16B.

FIG. 17 illustrates an example command console that can be used, forexample, as the command console in the example operating environment.

FIG. 18 illustrates the distal end of an example instrument havingimaging and EM sensing capabilities as described herein, for example,the instrument of FIGS. 16A-16C.

FIG. 19 illustrates an example luminal network in which location sensorregistration can be performed in accordance with aspects of thisdisclosure.

FIG. 20A is a flowchart illustrating an example method operable by asurgical robotic system, or component(s) thereof, for contra-laterallyregistering a location sensor coordinate system in accordance withaspects of this disclosure.

FIG. 20B is a flowchart illustrating an example method operable by asurgical robotic system, or component(s) thereof, for determiningwhether sufficient location data has been received to facilitatecontra-lateral registration in accordance with aspects of thisdisclosure.

FIG. 21 is a diagram illustrating location data with respect to a modelof a luminal network in accordance with aspects of this disclosure.

FIG. 22 is a diagram illustrating an example of registration of locationdata without preforming a contra-lateral registration process inaccordance with aspects of this disclosure.

FIG. 23 is a flowchart illustrating an example method operable by asurgical robotic system, or component(s) thereof, for pre-operativeplanning in accordance with aspects of this disclosure.

DETAILED DESCRIPTION

1. Overview

Aspects of the present disclosure may be integrated into arobotically-enabled medical system capable of performing a variety ofmedical procedures, including both minimally invasive, such aslaparoscopy, and non-invasive, such as endoscopy, procedures. Amongendoscopy procedures, the system may be capable of performingbronchoscopy, ureteroscopy, gastroscopy, etc.

In addition to performing the breadth of procedures, the system mayprovide additional benefits, such as enhanced imaging and guidance toassist the physician. Additionally, the system may provide the physicianwith the ability to perform the procedure from an ergonomic positionwithout the need for awkward arm motions and positions. Still further,the system may provide the physician with the ability to perform theprocedure with improved ease of use such that one or more of theinstruments of the system can be controlled by a single user.

Various embodiments will be described below in conjunction with thedrawings for purposes of illustration. It should be appreciated thatmany other implementations of the disclosed concepts are possible, andvarious advantages can be achieved with the disclosed implementations.Headings are included herein for reference and to aid in locatingvarious sections. These headings are not intended to limit the scope ofthe concepts described with respect thereto. Such concepts may haveapplicability throughout the entire specification.

A. Robotic System—Cart.

The robotically-enabled medical system may be configured in a variety ofways depending on the particular procedure. FIG. 1 illustrates anembodiment of a cart-based robotically-enabled system 10 arranged for adiagnostic and/or therapeutic bronchoscopy procedure. During abronchoscopy, the system 10 may comprise a cart 11 having one or morerobotic arms 12 to deliver a medical instrument, such as a steerableendoscope 13, which may be a procedure-specific bronchoscope forbronchoscopy, to a natural orifice access point (i.e., the mouth of thepatient positioned on a table in the present example) to deliverdiagnostic and/or therapeutic tools. As shown, the cart 11 may bepositioned proximate to the patient's upper torso in order to provideaccess to the access point. Similarly, the robotic arms 12 may beactuated to position the bronchoscope relative to the access point. Thearrangement in FIG. 1 may also be utilized when performing agastro-intestinal (GI) procedure with a gastroscope, a specializedendoscope for GI procedures. FIG. 2 depicts an example embodiment of thecart in greater detail.

With continued reference to FIG. 1 , once the cart 11 is properlypositioned, the robotic arms 12 may insert the steerable endoscope 13into the patient robotically, manually, or a combination thereof. Asshown, the steerable endoscope 13 may comprise at least two telescopingparts, such as an inner leader portion and an outer sheath portion, eachportion coupled to a separate instrument driver from the set ofinstrument drivers 28, each instrument driver coupled to the distal endof an individual robotic arm. This linear arrangement of the instrumentdrivers 28, which facilitates coaxially aligning the leader portion withthe sheath portion, creates a “virtual rail” 29 that may be repositionedin space by manipulating the one or more robotic arms 12 into differentangles and/or positions. The virtual rails described herein are depictedin the Figures using dashed lines, and accordingly the dashed lines donot depict any physical structure of the system. Translation of theinstrument drivers 28 along the virtual rail 29 telescopes the innerleader portion relative to the outer sheath portion or advances orretracts the endoscope 13 from the patient. The angle of the virtualrail 29 may be adjusted, translated, and pivoted based on clinicalapplication or physician preference. For example, in bronchoscopy, theangle and position of the virtual rail 29 as shown represents acompromise between providing physician access to the endoscope 13 whileminimizing friction that results from bending the endoscope 13 into thepatient's mouth.

The endoscope 13 may be directed down the patient's trachea and lungsafter insertion using precise commands from the robotic system untilreaching the target destination or operative site. In order to enhancenavigation through the patient's lung network and/or reach the desiredtarget, the endoscope 13 may be manipulated to telescopically extend theinner leader portion from the outer sheath portion to obtain enhancedarticulation and greater bend radius. The use of separate instrumentdrivers 28 also allows the leader portion and sheath portion to bedriven independent of each other.

For example, the endoscope 13 may be directed to deliver a biopsy needleto a target, such as, for example, a lesion or nodule within the lungsof a patient. The needle may be deployed down a working channel thatruns the length of the endoscope to obtain a tissue sample to beanalyzed by a pathologist. Depending on the pathology results,additional tools may be deployed down the working channel of theendoscope for additional biopsies. After identifying a nodule to bemalignant, the endoscope 13 may endoscopically deliver tools to resectthe potentially cancerous tissue. In some instances, diagnostic andtherapeutic treatments may need to be delivered in separate procedures.In those circumstances, the endoscope 13 may also be used to deliver afiducial to “mark” the location of the target nodule as well. In otherinstances, diagnostic and therapeutic treatments may be delivered duringthe same procedure.

The system 10 may also include a movable tower 30, which may beconnected via support cables to the cart 11 to provide support forcontrols, electronics, fluidics, optics, sensors, and/or power to thecart 11. Placing such functionality in the tower 30 allows for a smallerform factor cart 11 that may be more easily adjusted and/orre-positioned by an operating physician and his/her staff. Additionally,the division of functionality between the cart/table and the supporttower 30 reduces operating room clutter and facilitates improvingclinical workflow. While the cart 11 may be positioned close to thepatient, the tower 30 may be stowed in a remote location to stay out ofthe way during a procedure.

In support of the robotic systems described above, the tower 30 mayinclude component(s) of a computer-based control system that storescomputer program instructions, for example, within a non-transitorycomputer-readable storage medium such as a persistent magnetic storagedrive, solid state drive, etc. The execution of those instructions,whether the execution occurs in the tower 30 or the cart 11, may controlthe entire system or sub-system(s) thereof. For example, when executedby a processor of the computer system, the instructions may cause thecomponents of the robotics system to actuate the relevant carriages andarm mounts, actuate the robotics arms, and control the medicalinstruments. For example, in response to receiving the control signal,the motors in the joints of the robotics arms may position the arms intoa certain posture.

The tower 30 may also include a pump, flow meter, valve control, and/orfluid access in order to provide controlled irrigation and aspirationcapabilities to system that may be deployed through the endoscope 13.These components may also be controlled using the computer system oftower 30. In some embodiments, irrigation and aspiration capabilitiesmay be delivered directly to the endoscope 13 through separate cable(s).

The tower 30 may include a voltage and surge protector designed toprovide filtered and protected electrical power to the cart 11, therebyavoiding placement of a power transformer and other auxiliary powercomponents in the cart 11, resulting in a smaller, more moveable cart11.

The tower 30 may also include support equipment for the sensors deployedthroughout the robotic system 10. For example, the tower 30 may includeopto-electronics equipment for detecting, receiving, and processing datareceived from the optical sensors or cameras throughout the roboticsystem 10. In combination with the control system, such opto-electronicsequipment may be used to generate real-time images for display in anynumber of consoles deployed throughout the system, including in thetower 30. Similarly, the tower 30 may also include an electronicsubsystem for receiving and processing signals received from deployedelectromagnetic (EM) sensors. The tower 30 may also be used to house andposition an EM field generator for detection by EM sensors in or on themedical instrument.

The tower 30 may also include a console 31 in addition to other consolesavailable in the rest of the system, e.g., console mounted on top of thecart. The console 31 may include a user interface and a display screen,such as a touchscreen, for the physician operator. Consoles in system 10are generally designed to provide both robotic controls as well aspre-operative and real-time information of the procedure, such asnavigational and localization information of the endoscope 13. When theconsole 31 is not the only console available to the physician, it may beused by a second operator, such as a nurse, to monitor the health orvitals of the patient and the operation of system, as well as provideprocedure-specific data, such as navigational and localizationinformation.

The tower 30 may be coupled to the cart 11 and endoscope 13 through oneor more cables or connections (not shown). In some embodiments, thesupport functionality from the tower 30 may be provided through a singlecable to the cart 11, simplifying and de-cluttering the operating room.In other embodiments, specific functionality may be coupled in separatecabling and connections. For example, while power may be providedthrough a single power cable to the cart, the support for controls,optics, fluidics, and/or navigation may be provided through a separatecable.

FIG. 2 provides a detailed illustration of an embodiment of the cartfrom the cart-based robotically-enabled system shown in FIG. 1 . Thecart 11 generally includes an elongated support structure 14 (oftenreferred to as a “column”), a cart base 15, and a console 16 at the topof the column 14. The column 14 may include one or more carriages, suchas a carriage 17 (alternatively “arm support”) for supporting thedeployment of one or more robotic arms 12 (three shown in FIG. 2 ). Thecarriage 17 may include individually configurable arm mounts that rotatealong a perpendicular axis to adjust the base of the robotic arms 12 forbetter positioning relative to the patient. The carriage 17 alsoincludes a carriage interface 19 that allows the carriage 17 tovertically translate along the column 14.

The carriage interface 19 is connected to the column 14 through slots,such as slot 20, that are positioned on opposite sides of the column 14to guide the vertical translation of the carriage 17. The slot 20contains a vertical translation interface to position and hold thecarriage at various vertical heights relative to the cart base 15.Vertical translation of the carriage 17 allows the cart 11 to adjust thereach of the robotic arms 12 to meet a variety of table heights, patientsizes, and physician preferences. Similarly, the individuallyconfigurable arm mounts on the carriage 17 allow the robotic arm base 21of robotic arms 12 to be angled in a variety of configurations.

In some embodiments, the slot 20 may be supplemented with slot coversthat are flush and parallel to the slot surface to prevent dirt andfluid ingress into the internal chambers of the column 14 and thevertical translation interface as the carriage 17 vertically translates.The slot covers may be deployed through pairs of spring spoolspositioned near the vertical top and bottom of the slot 20. The coversare coiled within the spools until deployed to extend and retract fromtheir coiled state as the carriage 17 vertically translates up and down.The spring-loading of the spools provides force to retract the coverinto a spool when carriage 17 translates towards the spool, while alsomaintaining a tight seal when the carriage 17 translates away from thespool. The covers may be connected to the carriage 17 using, forexample, brackets in the carriage interface 19 to ensure properextension and retraction of the cover as the carriage 17 translates.

The column 14 may internally comprise mechanisms, such as gears andmotors, that are designed to use a vertically aligned lead screw totranslate the carriage 17 in a mechanized fashion in response to controlsignals generated in response to user inputs, e.g., inputs from theconsole 16.

The robotic arms 12 may generally comprise robotic arm bases 21 and endeffectors 22, separated by a series of linkages 23 that are connected bya series of joints 24, each joint comprising an independent actuator,each actuator comprising an independently controllable motor. Eachindependently controllable joint represents an independent degree offreedom available to the robotic arm. Each of the arms 12 have sevenjoints, and thus provide seven degrees of freedom. A multitude of jointsresult in a multitude of degrees of freedom, allowing for “redundant”degrees of freedom. Redundant degrees of freedom allow the robotic arms12 to position their respective end effectors 22 at a specific position,orientation, and trajectory in space using different linkage positionsand joint angles. This allows for the system to position and direct amedical instrument from a desired point in space while allowing thephysician to move the arm joints into a clinically advantageous positionaway from the patient to create greater access, while avoiding armcollisions.

The cart base 15 balances the weight of the column 14, carriage 17, andarms 12 over the floor. Accordingly, the cart base 15 houses heaviercomponents, such as electronics, motors, power supply, as well ascomponents that either enable movement and/or immobilize the cart. Forexample, the cart base 15 includes rollable wheel-shaped casters 25 thatallow for the cart to easily move around the room prior to a procedure.After reaching the appropriate position, the casters 25 may beimmobilized using wheel locks to hold the cart 11 in place during theprocedure.

Positioned at the vertical end of column 14, the console 16 allows forboth a user interface for receiving user input and a display screen (ora dual-purpose device such as, for example, a touchscreen 26) to providethe physician user with both pre-operative and intra-operative data.Potential pre-operative data on the touchscreen 26 may includepre-operative plans, navigation and mapping data derived frompre-operative computerized tomography (CT) scans, and/or notes frompre-operative patient interviews. Intra-operative data on display mayinclude optical information provided from the tool, sensor andcoordinate information from sensors, as well as vital patientstatistics, such as respiration, heart rate, and/or pulse. The console16 may be positioned and tilted to allow a physician to access theconsole from the side of the column 14 opposite carriage 17. From thisposition, the physician may view the console 16, robotic arms 12, andpatient while operating the console 16 from behind the cart 11. Asshown, the console 16 also includes a handle 27 to assist withmaneuvering and stabilizing cart 11.

FIG. 3 illustrates an embodiment of a robotically-enabled system 10arranged for ureteroscopy. In a ureteroscopic procedure, the cart 11 maybe positioned to deliver a ureteroscope 32, a procedure-specificendoscope designed to traverse a patient's urethra and ureter, to thelower abdominal area of the patient. In a ureteroscopy, it may bedesirable for the ureteroscope 32 to be directly aligned with thepatient's urethra to reduce friction and forces on the sensitive anatomyin the area. As shown, the cart 11 may be aligned at the foot of thetable to allow the robotic arms 12 to position the ureteroscope 32 fordirect linear access to the patient's urethra. From the foot of thetable, the robotic arms 12 may insert the ureteroscope 32 along thevirtual rail 33 directly into the patient's lower abdomen through theurethra.

After insertion into the urethra, using similar control techniques as inbronchoscopy, the ureteroscope 32 may be navigated into the bladder,ureters, and/or kidneys for diagnostic and/or therapeutic applications.For example, the ureteroscope 32 may be directed into the ureter andkidneys to break up kidney stone build up using laser or ultrasoniclithotripsy device deployed down the working channel of the ureteroscope32. After lithotripsy is complete, the resulting stone fragments may beremoved using baskets deployed down the ureteroscope 32.

FIG. 4 illustrates an embodiment of a robotically-enabled systemsimilarly arranged for a vascular procedure. In a vascular procedure,the system 10 may be configured such the cart 11 may deliver a medicalinstrument 34, such as a steerable catheter, to an access point in thefemoral artery in the patient's leg. The femoral artery presents both alarger diameter for navigation as well as relatively less circuitous andtortuous path to the patient's heart, which simplifies navigation. As ina ureteroscopic procedure, the cart 11 may be positioned towards thepatient's legs and lower abdomen to allow the robotic arms 12 to providea virtual rail 35 with direct linear access to the femoral artery accesspoint in the patient's thigh/hip region. After insertion into theartery, the medical instrument 34 may be directed and inserted bytranslating the instrument drivers 28. Alternatively, the cart may bepositioned around the patient's upper abdomen in order to reachalternative vascular access points, such as, for example, the carotidand brachial arteries near the shoulder and wrist.

B. Robotic System—Table.

Embodiments of the robotically-enabled medical system may alsoincorporate the patient's table. Incorporation of the table reduces theamount of capital equipment within the operating room by removing thecart, which allows greater access to the patient. FIG. 5 illustrates anembodiment of such a robotically-enabled system arranged for abronchoscopy procedure. System 36 includes a support structure or column37 for supporting platform 38 (shown as a “table” or “bed”) over thefloor. Much like in the cart-based systems, the end effectors of therobotic arms 39 of the system 36 comprise instrument drivers 42 that aredesigned to manipulate an elongated medical instrument, such as abronchoscope 40 in FIG. 5 , through or along a virtual rail 41 formedfrom the linear alignment of the instrument drivers 42. In practice, aC-arm for providing fluoroscopic imaging may be positioned over thepatient's upper abdominal area by placing the emitter and detectoraround table 38.

FIG. 6 provides an alternative view of the system 36 without the patientand medical instrument for discussion purposes. As shown, the column 37may include one or more carriages 43 shown as ring-shaped in the system36, from which the one or more robotic arms 39 may be based. Thecarriages 43 may translate along a vertical column interface 44 thatruns the length of the column 37 to provide different vantage pointsfrom which the robotic arms 39 may be positioned to reach the patient.The carriage(s) 43 may rotate around the column 37 using a mechanicalmotor positioned within the column 37 to allow the robotic arms 39 tohave access to multiples sides of the table 38, such as, for example,both sides of the patient. In embodiments with multiple carriages, thecarriages may be individually positioned on the column and may translateand/or rotate independent of the other carriages. While carriages 43need not surround the column 37 or even be circular, the ring-shape asshown facilitates rotation of the carriages 43 around the column 37while maintaining structural balance. Rotation and translation of thecarriages 43 allows the system to align the medical instruments, such asendoscopes and laparoscopes, into different access points on thepatient.

The arms 39 may be mounted on the carriages through a set of arm mounts45 comprising a series of joints that may individually rotate and/ortelescopically extend to provide additional configurability to therobotic arms 39. Additionally, the arm mounts 45 may be positioned onthe carriages 43 such that, when the carriages 43 are appropriatelyrotated, the arm mounts 45 may be positioned on either the same side oftable 38 (as shown in FIG. 6 ), on opposite sides of table 38 (as shownin FIG. 9 ), or on adjacent sides of the table 38 (not shown).

The column 37 structurally provides support for the table 38, and a pathfor vertical translation of the carriages. Internally, the column 37 maybe equipped with lead screws for guiding vertical translation of thecarriages, and motors to mechanize the translation of said carriagesbased the lead screws. The column 37 may also convey power and controlsignals to the carriage 43 and robotic arms 39 mounted thereon.

The table base 46 serves a similar function as the cart base 15 in cart11 shown in FIG. 2 , housing heavier components to balance the table/bed38, the column 37, the carriages 43, and the robotic arms 39. The tablebase 46 may also incorporate rigid casters to provide stability duringprocedures. Deployed from the bottom of the table base 46, the castersmay extend in opposite directions on both sides of the base 46 andretract when the system 36 needs to be moved.

Continuing with FIG. 6 , the system 36 may also include a tower (notshown) that divides the functionality of system 36 between table andtower to reduce the form factor and bulk of the table. As in earlierdisclosed embodiments, the tower may provide a variety of supportfunctionalities to table, such as processing, computing, and controlcapabilities, power, fluidics, and/or optical and sensor processing. Thetower may also be movable to be positioned away from the patient toimprove physician access and de-clutter the operating room.Additionally, placing components in the tower allows for more storagespace in the table base for potential stowage of the robotic arms. Thetower may also include a console that provides both a user interface foruser input, such as keyboard and/or pendant, as well as a display screen(or touchscreen) for pre-operative and intra-operative information, suchas real-time imaging, navigation, and tracking information.

In some embodiments, a table base may stow and store the robotic armswhen not in use. FIG. 7 illustrates a system 47 that stows robotic armsin an embodiment of the table-based system. In system 47, carriages 48may be vertically translated into base 49 to stow robotic arms 50, armmounts 51, and the carriages 48 within the base 49. Base covers 52 maybe translated and retracted open to deploy the carriages 48, arm mounts51, and arms 50 around column 53, and closed to stow to protect themwhen not in use. The base covers 52 may be sealed with a membrane 54along the edges of its opening to prevent dirt and fluid ingress whenclosed.

FIG. 8 illustrates an embodiment of a robotically-enabled table-basedsystem configured for a ureteroscopy procedure. In a ureteroscopy, thetable 38 may include a swivel portion 55 for positioning a patientoff-angle from the column 37 and table base 46. The swivel portion 55may rotate or pivot around a pivot point (e.g., located below thepatient's head) in order to position the bottom portion of the swivelportion 55 away from the column 37. For example, the pivoting of theswivel portion 55 allows a C-arm (not shown) to be positioned over thepatient's lower abdomen without competing for space with the column (notshown) below table 38. By rotating the carriage 35 (not shown) aroundthe column 37, the robotic arms 39 may directly insert a ureteroscope 56along a virtual rail 57 into the patient's groin area to reach theurethra. In a ureteroscopy, stirrups 58 may also be fixed to the swivelportion 55 of the table 38 to support the position of the patient's legsduring the procedure and allow clear access to the patient's groin area.

In a laparoscopic procedure, through small incision(s) in the patient'sabdominal wall, minimally invasive instruments (elongated in shape toaccommodate the size of the one or more incisions) may be inserted intothe patient's anatomy. After inflation of the patient's abdominalcavity, the instruments, often referred to as laparoscopes, may bedirected to perform surgical tasks, such as grasping, cutting, ablating,suturing, etc. FIG. 9 illustrates an embodiment of a robotically-enabledtable-based system configured for a laparoscopic procedure. As shown inFIG. 9 , the carriages 43 of the system 36 may be rotated and verticallyadjusted to position pairs of the robotic arms 39 on opposite sides ofthe table 38, such that laparoscopes 59 may be positioned using the armmounts 45 to be passed through minimal incisions on both sides of thepatient to reach his/her abdominal cavity.

To accommodate laparoscopic procedures, the robotically-enabled tablesystem may also tilt the platform to a desired angle. FIG. 10illustrates an embodiment of the robotically-enabled medical system withpitch or tilt adjustment. As shown in FIG. 10 , the system 36 mayaccommodate tilt of the table 38 to position one portion of the table ata greater distance from the floor than the other. Additionally, the armmounts 45 may rotate to match the tilt such that the arms 39 maintainthe same planar relationship with table 38. To accommodate steeperangles, the column 37 may also include telescoping portions 60 thatallow vertical extension of column 37 to keep the table 38 from touchingthe floor or colliding with base 46.

FIG. 11 provides a detailed illustration of the interface between thetable 38 and the column 37. Pitch rotation mechanism 61 may beconfigured to alter the pitch angle of the table 38 relative to thecolumn 37 in multiple degrees of freedom. The pitch rotation mechanism61 may be enabled by the positioning of orthogonal axes 1, 2 at thecolumn-table interface, each axis actuated by a separate motor 3, 4responsive to an electrical pitch angle command. Rotation along onescrew 5 would enable tilt adjustments in one axis 1, while rotationalong the other screw 6 would enable tilt adjustments along the otheraxis 2.

For example, pitch adjustments are particularly useful when trying toposition the table in a Trendelenburg position, i.e., position thepatient's lower abdomen at a higher position from the floor than thepatient's lower abdomen, for lower abdominal surgery. The Trendelenburgposition causes the patient's internal organs to slide towards his/herupper abdomen through the force of gravity, clearing out the abdominalcavity for minimally invasive tools to enter and perform lower abdominalsurgical procedures, such as laparoscopic prostatectomy.

C. Instrument Driver & Interface.

The end effectors of the system's robotic arms comprise (i) aninstrument driver (alternatively referred to as “instrument drivemechanism” or “instrument device manipulator”) that incorporateelectro-mechanical means for actuating the medical instrument and (ii) aremovable or detachable medical instrument which may be devoid of anyelectro-mechanical components, such as motors. This dichotomy may bedriven by the need to sterilize medical instruments used in medicalprocedures, and the inability to adequately sterilize expensive capitalequipment due to their intricate mechanical assemblies and sensitiveelectronics. Accordingly, the medical instruments may be designed to bedetached, removed, and interchanged from the instrument driver (and thusthe system) for individual sterilization or disposal by the physician orthe physician's staff. In contrast, the instrument drivers need not bechanged or sterilized, and may be draped for protection.

FIG. 12 illustrates an example instrument driver. Positioned at thedistal end of a robotic arm, instrument driver 62 comprises of one ormore drive units 63 arranged with parallel axes to provide controlledtorque to a medical instrument via drive shafts 64. Each drive unit 63comprises an individual drive shaft 64 for interacting with theinstrument, a gear head 65 for converting the motor shaft rotation to adesired torque, a motor 66 for generating the drive torque, an encoder67 to measure the speed of the motor shaft and provide feedback to thecontrol circuitry, and control circuitry 68 for receiving controlsignals and actuating the drive unit. Each drive unit 63 beingindependent controlled and motorized, the instrument driver 62 mayprovide multiple (four as shown in FIG. 12 ) independent drive outputsto the medical instrument. In operation, the control circuitry 68 wouldreceive a control signal, transmit a motor signal to the motor 66,compare the resulting motor speed as measured by the encoder 67 with thedesired speed, and modulate the motor signal to generate the desiredtorque.

For procedures that require a sterile environment, the robotic systemmay incorporate a drive interface, such as a sterile adapter connectedto a sterile drape, that sits between the instrument driver and themedical instrument. The chief purpose of the sterile adapter is totransfer angular motion from the drive shafts of the instrument driverto the drive inputs of the instrument while maintaining physicalseparation, and thus sterility, between the drive shafts and driveinputs. Accordingly, an example sterile adapter may comprise of a seriesof rotational inputs and outputs intended to be mated with the driveshafts of the instrument driver and drive inputs on the instrument.Connected to the sterile adapter, the sterile drape, comprised of athin, flexible material such as transparent or translucent plastic, isdesigned to cover the capital equipment, such as the instrument driver,robotic arm, and cart (in a cart-based system) or table (in atable-based system). Use of the drape would allow the capital equipmentto be positioned proximate to the patient while still being located inan area not requiring sterilization (i.e., non-sterile field). On theother side of the sterile drape, the medical instrument may interfacewith the patient in an area requiring sterilization (i.e., sterilefield).

D. Medical Instrument.

FIG. 13 illustrates an example medical instrument with a pairedinstrument driver. Like other instruments designed for use with arobotic system, medical instrument 70 comprises an elongated shaft 71(or elongate body) and an instrument base 72. The instrument base 72,also referred to as an “instrument handle” due to its intended designfor manual interaction by the physician, may generally compriserotatable drive inputs 73, e.g., receptacles, pulleys or spools, thatare designed to be mated with drive outputs 74 that extend through adrive interface on instrument driver 75 at the distal end of robotic arm76. When physically connected, latched, and/or coupled, the mated driveinputs 73 of instrument base 72 may share axes of rotation with thedrive outputs 74 in the instrument driver 75 to allow the transfer oftorque from drive outputs 74 to drive inputs 73. In some embodiments,the drive outputs 74 may comprise splines that are designed to mate withreceptacles on the drive inputs 73.

The elongated shaft 71 is designed to be delivered through either ananatomical opening or lumen, e.g., as in endoscopy, or a minimallyinvasive incision, e.g., as in laparoscopy. The elongated shaft 66 maybe either flexible (e.g., having properties similar to an endoscope) orrigid (e.g., having properties similar to a laparoscope) or contain acustomized combination of both flexible and rigid portions. Whendesigned for laparoscopy, the distal end of a rigid elongated shaft maybe connected to an end effector comprising a jointed wrist formed from aclevis with an axis of rotation and a surgical tool, such as, forexample, a grasper or scissors, that may be actuated based on force fromthe tendons as the drive inputs rotate in response to torque receivedfrom the drive outputs 74 of the instrument driver 75. When designed forendoscopy, the distal end of a flexible elongated shaft may include asteerable or controllable bending section that may be articulated andbent based on torque received from the drive outputs 74 of theinstrument driver 75.

Torque from the instrument driver 75 is transmitted down the elongatedshaft 71 using tendons within the shaft 71. These individual tendons,such as pull wires, may be individually anchored to individual driveinputs 73 within the instrument handle 72. From the handle 72, thetendons are directed down one or more pull lumens within the elongatedshaft 71 and anchored at the distal portion of the elongated shaft 71.In laparoscopy, these tendons may be coupled to a distally mounted endeffector, such as a wrist, grasper, or scissor. Under such anarrangement, torque exerted on drive inputs 73 would transfer tension tothe tendon, thereby causing the end effector to actuate in some way. Inlaparoscopy, the tendon may cause a joint to rotate about an axis,thereby causing the end effector to move in one direction or another.Alternatively, the tendon may be connected to one or more jaws of agrasper at distal end of the elongated shaft 71, where tension from thetendon cause the grasper to close.

In endoscopy, the tendons may be coupled to a bending or articulatingsection positioned along the elongated shaft 71 (e.g., at the distalend) via adhesive, control ring, or other mechanical fixation. Whenfixedly attached to the distal end of a bending section, torque exertedon drive inputs 73 would be transmitted down the tendons, causing thesofter, bending section (sometimes referred to as the articulablesection or region) to bend or articulate. Along the non-bendingsections, it may be advantageous to spiral or helix the individual pulllumens that direct the individual tendons along (or inside) the walls ofthe endoscope shaft to balance the radial forces that result fromtension in the pull wires. The angle of the spiraling and/or spacingthere between may be altered or engineered for specific purposes,wherein tighter spiraling exhibits lesser shaft compression under loadforces, while lower amounts of spiraling results in greater shaftcompression under load forces, but also exhibits limits bending. On theother end of the spectrum, the pull lumens may be directed parallel tothe longitudinal axis of the elongated shaft 71 to allow for controlledarticulation in the desired bending or articulable sections.

In endoscopy, the elongated shaft 71 houses a number of components toassist with the robotic procedure. The shaft may comprise of a workingchannel for deploying surgical tools, irrigation, and/or aspiration tothe operative region at the distal end of the shaft 71. The shaft 71 mayalso accommodate wires and/or optical fibers to transfer signals to/froman optical assembly at the distal tip, which may include of an opticalcamera. The shaft 71 may also accommodate optical fibers to carry lightfrom proximally-located light sources, such as light emitting diodes, tothe distal end of the shaft.

At the distal end of the instrument 70, the distal tip may also comprisethe opening of a working channel for delivering tools for diagnosticand/or therapy, irrigation, and aspiration to an operative site. Thedistal tip may also include a port for a camera, such as a fiberscope ora digital camera, to capture images of an internal anatomical space.Relatedly, the distal tip may also include ports for light sources forilluminating the anatomical space when using the camera.

In the example of FIG. 13 , the drive shaft axes, and thus the driveinput axes, are orthogonal to the axis of the elongated shaft. Thisarrangement, however, complicates roll capabilities for the elongatedshaft 71. Rolling the elongated shaft 71 along its axis while keepingthe drive inputs 73 static results in undesirable tangling of thetendons as they extend off the drive inputs 73 and enter pull lumenswithin the elongate shaft 71. The resulting entanglement of such tendonsmay disrupt any control algorithms intended to predict movement of theflexible elongate shaft during an endoscopic procedure.

FIG. 14 illustrates an alternative design for an instrument driver andinstrument where the axes of the drive units are parallel to the axis ofthe elongated shaft of the instrument. As shown, a circular instrumentdriver 80 comprises four drive units with their drive outputs 81 alignedin parallel at the end of a robotic arm 82. The drive units, and theirrespective drive outputs 81, are housed in a rotational assembly 83 ofthe instrument driver 80 that is driven by one of the drive units withinthe assembly 83. In response to torque provided by the rotational driveunit, the rotational assembly 83 rotates along a circular bearing thatconnects the rotational assembly 83 to the non-rotational portion 84 ofthe instrument driver. Power and controls signals may be communicatedfrom the non-rotational portion 84 of the instrument driver 80 to therotational assembly 83 through electrical contacts may be maintainedthrough rotation by a brushed slip ring connection (not shown). In otherembodiments, the rotational assembly 83 may be responsive to a separatedrive unit that is integrated into the non-rotatable portion 84, andthus not in parallel to the other drive units. The rotational mechanism83 allows the instrument driver 80 to rotate the drive units, and theirrespective drive outputs 81, as a single unit around an instrumentdriver axis 85.

Like earlier disclosed embodiments, an instrument 86 may comprise of anelongated shaft portion 88 and an instrument base 87 (shown with atransparent external skin for discussion purposes) comprising aplurality of drive inputs 89 (such as receptacles, pulleys, and spools)that are configured to receive the drive outputs 81 in the instrumentdriver 80. Unlike prior disclosed embodiments, instrument shaft 88extends from the center of instrument base 87 with an axis substantiallyparallel to the axes of the drive inputs 89, rather than orthogonal asin the design of FIG. 13 .

When coupled to the rotational assembly 83 of the instrument driver 80,the medical instrument 86, comprising instrument base 87 and instrumentshaft 88, rotates in combination with the rotational assembly 83 aboutthe instrument driver axis 85. Since the instrument shaft 88 ispositioned at the center of instrument base 87, the instrument shaft 88is coaxial with instrument driver axis 85 when attached. Thus, rotationof the rotational assembly 83 causes the instrument shaft 88 to rotateabout its own longitudinal axis. Moreover, as the instrument base 87rotates with the instrument shaft 88, any tendons connected to the driveinputs 89 in the instrument base 87 are not tangled during rotation.Accordingly, the parallelism of the axes of the drive outputs 81, driveinputs 89, and instrument shaft 88 allows for the shaft rotation withouttangling any control tendons.

E. Navigation and Control.

Traditional endoscopy may involve the use of fluoroscopy (e.g., as maybe delivered through a C-arm) and other forms of radiation-based imagingmodalities to provide endoluminal guidance to an operator physician. Incontrast, the robotic systems contemplated by this disclosure canprovide for non-radiation-based navigational and localization means toreduce physician exposure to radiation and reduce the amount ofequipment within the operating room. As used herein, the term“localization” may refer to determining and/or monitoring the positionof objects in a reference coordinate system. Technologies such aspre-operative mapping, computer vision, real-time EM tracking, and robotcommand data may be used individually or in combination to achieve aradiation-free operating environment. In other cases, whereradiation-based imaging modalities are still used, the pre-operativemapping, computer vision, real-time EM tracking, and robot command datamay be used individually or in combination to improve upon theinformation obtained solely through radiation-based imaging modalities.

FIG. 15 is a block diagram illustrating a localization system 90 thatestimates a location of one or more elements of the robotic system, suchas the location of the instrument, in accordance to an exampleembodiment. The localization system 90 may be a set of one or morecomputer devices configured to execute one or more instructions. Thecomputer devices may be embodied by a processor (or processors) andcomputer-readable memory in one or more components discussed above. Byway of example and not limitation, the computer devices may be in thetower 30 shown in FIG. 1 , the cart shown in FIGS. 1-4 , the beds shownin FIGS. 5-10 , etc.

As shown in FIG. 15 , the localization system 90 may include alocalization module 95 that processes input data 91-94 to generatelocation data 96 for the distal tip of a medical instrument. Thelocation data 96 may be data or logic that represents a location and/ororientation of the distal end of the instrument relative to a frame ofreference. The frame of reference can be a frame of reference relativeto the anatomy of the patient or to a known object, such as an EM fieldgenerator (see discussion below for the EM field generator). Thelocation data 96 may also be referred to herein as “state data” whichdescribes a current state of the distal tip of the medical instrumentwith respect to a model (e.g., a skeletal model) of the anatomy of thepatient. The state data may include information such as a position andorientation of the distal tip of the medical instrument for a givensample period. For example, when the patient's anatomy is modeled usinga skeletal model based on a midpoint of the luminal network, theposition may take the form of a segment ID and a depth along thesegment.

The various input data 91-94 are now described in greater detail.Pre-operative mapping may be accomplished through the use of thecollection of low dose CT scans. Pre-operative CT scans arereconstructed into three-dimensional (3D) images, which are visualized,e.g., as “slices” of a cutaway view of the patient's internal anatomy.When analyzed in the aggregate, image-based models for anatomicalcavities, spaces and structures of the patient's anatomy, such as apatient lung network, may be generated. Techniques such as center-linegeometry may be determined and approximated from the CT images todevelop a 3D volume of the patient's anatomy, referred to aspreoperative model data 91. The use of center-line geometry is discussedin U.S. patent application Ser. No. 14/523,760, the contents of whichare herein incorporated in its entirety. Network topological models mayalso be derived from the CT-images, and are particularly appropriate forbronchoscopy.

In some embodiments, the instrument may be equipped with a camera toprovide vision data 92. The localization module 95 may process thevision data to enable one or more vision-based location tracking. Forexample, the preoperative model data may be used in conjunction with thevision data 92 to enable computer vision-based tracking of the medicalinstrument (e.g., an endoscope or an instrument advance through aworking channel of the endoscope). For example, using the preoperativemodel data 91, the robotic system may generate a library of expectedendoscopic images from the model based on the expected path of travel ofthe endoscope, each image linked to a location within the model.Intra-operatively, this library may be referenced by the robotic systemin order to compare real-time images captured at the camera (e.g., acamera at a distal end of the endoscope) to those in the image libraryto assist localization.

Other computer vision-based tracking techniques use feature tracking todetermine motion of the camera, and thus the endoscope. Some feature ofthe localization module 95 may identify circular geometries in thepreoperative model data 91 that correspond to anatomical lumens andtrack the change of those geometries to determine which anatomical lumenwas selected, as well as the relative rotational and/or translationalmotion of the camera. Use of a topological map may further enhancevision-based algorithms or techniques.

Optical flow, another computer vision-based technique, may analyze thedisplacement and translation of image pixels in a video sequence in thevision data 92 to infer camera movement. Examples of optical flowtechniques may include motion detection, object segmentationcalculations, luminance, motion compensated encoding, stereo disparitymeasurement, etc. Through the comparison of multiple frames overmultiple iterations, movement and location of the camera (and thus theendoscope) may be determined.

The localization module 95 may use real-time EM tracking to generate areal-time location of the endoscope in a global coordinate system thatmay be registered to the patient's anatomy, represented by thepreoperative model. In EM tracking, an EM sensor (or tracker) comprisingof one or more sensor coils embedded in one or more locations andorientations in a medical instrument (e.g., an endoscopic tool) measuresthe variation in the EM field created by one or more static EM fieldgenerators positioned at a known location. The location informationdetected by the EM sensors is stored as EM data 93. The EM fieldgenerator (or transmitter), may be placed close to the patient to createa low intensity magnetic field that the embedded sensor may detect. Themagnetic field induces small currents in the sensor coils of the EMsensor, which may be analyzed to determine the distance and anglebetween the EM sensor and the EM field generator. These distances andorientations may be intra-operatively “registered” to the patientanatomy (e.g., the preoperative model) in order to determine thegeometric transformation that aligns a single location in the coordinatesystem with a position in the pre-operative model of the patient'sanatomy. Once registered, an embedded EM tracker in one or morepositions of the medical instrument (e.g., the distal tip of anendoscope) may provide real-time indications of the progression of themedical instrument through the patient's anatomy.

Robotic command and kinematics data 94 may also be used by thelocalization module 95 to provide localization data 96 for the roboticsystem. Device pitch and yaw resulting from articulation commands may bedetermined during pre-operative calibration. Intra-operatively, thesecalibration measurements may be used in combination with known insertiondepth information to estimate the position of the instrument.Alternatively, these calculations may be analyzed in combination withEM, vision, and/or topological modeling to estimate the position of themedical instrument within the network.

As FIG. 15 shows, a number of other input data can be used by thelocalization module 95. For example, although not shown in FIG. 15 , aninstrument utilizing shape-sensing fiber can provide shape data that thelocalization module 95 can use to determine the location and shape ofthe instrument.

The localization module 95 may use the input data 91-94 incombination(s). In some cases, such a combination may use aprobabilistic approach where the localization module 95 assigns aconfidence weight to the location determined from each of the input data91-94. Thus, where the EM data may not be reliable (as may be the casewhere there is EM interference) the confidence of the locationdetermined by the EM data 93 can be decrease and the localization module95 may rely more heavily on the vision data 92 and/or the roboticcommand and kinematics data 94.

As discussed above, the robotic systems discussed herein may be designedto incorporate a combination of one or more of the technologies above.The robotic system's computer-based control system, based in the tower,bed and/or cart, may store computer program instructions, for example,within a non-transitory computer-readable storage medium such as apersistent magnetic storage drive, solid state drive, or the like, that,upon execution, cause the system to receive and analyze sensor data anduser commands, generate control signals throughout the system, anddisplay the navigational and localization data, such as the position ofthe instrument within the global coordinate system, anatomical map, etc.

2. Introduction to Registration of Location Sensors

Embodiments of the disclosure relate to systems and techniques forregistering a coordinate system used by one or more location sensorswith another coordinate system, such as a coordinate system used by ananatomical model. Registration may refer to a transformation which canbe applied to location sensor data to map the location sensor data intothe coordinate system of the anatomical model. Thus, registration can beused by a system to determine the location of one or more locationsensor(s) with respect to the anatomical model based on the locationsensor data. Location sensor(s) may be used to localize the distal endof an instrument to an anatomical location during a medical procedure.The location sensor(s) may be positioned at or near the distal end ofthe instrument or may be positioned remote from the distal end of theinstrument. Examples of location sensors which may be positioned at ornear the distal end of the instrument include: EM sensors, vision-basedlocation sensors (e.g., a camera), shape sensing fibers, etc. Examplesof location sensors which may be positioned remote from the distal endof the instrument include fluoroscopic imaging devices, robotic dataused to control the position of the instrument via one or moreinstrument manipulators, etc.

The location sensors may be configured to generate location dataindicative of the location of the distal end of the instrument withrespect to a location sensor coordinate system. When the locationsensors are collocated with the distal end of the instrument, thelocation data may be representative of the location of the locationsensors themselves, which can then be used to determine the location ofthe distal end of the instrument. In certain embodiments, the locationsensor coordinate system may comprise a set of axes and an origin, whichmay be defined based on the particular technology used to implement thelocation sensors.

For example, EM sensors located in or on the instrument may beconfigured to measure an EM field generated by an EM field generator.The properties of the EM field, and thus, the EM values measured by theEM sensors, may be defined with respect to the location and orientationof the EM field generator. Thus, the positioning of the EM fieldgenerator may affect the values measured by the EM sensors and may alsodefine the location and orientation of the EM coordinate system.

As described above, a patient's luminal network may be pre-operativelymapped using, for example, low dose CT scans to produce a model of theluminal network. Since the model may be produced via a differenttechnique than used to locate the distal end of the instrument, themodel coordinate system may not be aligned with the location sensorcoordinate system. Accordingly, in order to use the location sensorcoordinate system to track the location of the instrument with respectto the model, certain aspects of this disclosure relate to “registering”the location sensor coordinate system to the model coordinate system.This registration may include, for example, a translation and/or arotation, which can be applied to the location data in order to map thelocation data from the location sensor coordinate system into the modelcoordinate system.

Since the model of the luminal network provides a mapping of thepatient's luminal network, the model coordinate system is “anchored” ordefined with respect to the patient. That is, the frame of reference forthe model coordinate system is based on the location and/or orientationof the patient during the procedure. One challenge to registering thelocation sensor coordinate system to the model coordinate system is thatthe frame of reference for the location sensor coordinate system may notbe “anchored” or predefined with respect to the patient. For example,when the location sensor is embodied as an EM sensor, the frame ofreference for the EM coordinate system may be the EM field generator.However, in certain implementations, the EM field generator may befreely positioned within a certain area so that the EM field generatorcan be positioned out of the path of other elements of the roboticsurgical system (e.g., robotic arms, C-arm, etc.). Since the position ofthe EM field generator, and thus the frame of reference of the EMcoordinate system is not predefined, the system may be configured toperform a process to register the EM coordinate system to the modelcoordinate system.

One technique for registering the EM coordinate system to the modelcoordinate system may include a preoperative step of identifying aplurality of locations within the preoperative model and anintraoperative step of providing instructions to a user to drive theinstrument to each of these locations. The system may instruct the userto drive the instrument to each of the locations, relying on other formsof navigation (e.g., camera feedback), and the system may further beconfigured to receive input from the user confirming when the instrumentis located at each of the identified locations. Using the confirmationsreceived from the user, the EM data, and the identified locations withinthe model, the system may determine a registration that maps the EM datato the identified locations. This registration can then be used to mapthe EM data representing the location of the distal end of theinstrument to the model for the remainder of the procedure.

However, the above-described registration process may be complicated andtime consuming for the user. For example, in order to provide asufficiently robust registration, the system may be required to identifya relatively large number of locations (e.g., 6 or more locations) whichare spatially diverse (e.g., the identified locations may be required tobe at least a certain distance apart from each other). Accordingly,certain aspects of this disclosure relate to systems and techniqueswhich may provide a registration between a location sensor coordinatesystem and a model coordinate system via a simplified process.

A. EM Navigation-Guided Bronchoscopy.

Hereinafter, the registration of location sensors will be described withrespect to the embodiment of the registration of EM sensors for use inan EM navigation-guided bronchoscopic procedure. However, aspects ofthis disclosure may also apply to other location sensors which canproduce location data within a corresponding location sensor coordinatesystem, as well as to other medical types of medical procedures.

A bronchoscope can include a light source and a small camera that allowsa physician to inspect a patient's windpipe and airways. Patient traumacan occur if the precise location of the bronchoscope within the patientairways is not known. To ascertain the location of the bronchoscope,image-based bronchoscopy guidance systems can use data from thebronchoscope camera to perform local registrations (e.g., registrationsat a particular location within a luminal network) at bifurcations ofpatient airways and so beneficially can be less susceptible to positionerrors due to patient breathing motion. However, as image-based guidancemethods rely on the bronchoscope video, they can be affected byartifacts in bronchoscope video caused by patient coughing or mucousobstruction, etc.

EM navigation-guided bronchoscopy is a type of bronchoscopic procedurethat implements EM technology to localize and guide endoscopic tools orcatheters through the bronchial pathways of the lung. EMnavigation-guided bronchoscopy systems can use an EM field generatorthat emits a low-intensity, varying EM field and establishes theposition of the tracking volume around the luminal network of thepatient. The EM field is a physical field produced by electricallycharged objects that affects the behavior of charged objects in thevicinity of the field. EM sensors attached to the instrument whenpositioned within the generated field can be used to track locations andorientations of the instrument within the EM field. Small currents areinduced in the EM sensors by the varying electromagnetic field. Thecharacteristics of these electrical signals are dependent on thedistance and angle between a sensor and the EM field generator.Accordingly, an EM navigation-guided bronchoscopy system can include anEM field generator, a steerable instrument having one or more EM sensorsat or near its distal tip, and a guidance computing system. The EM fieldgenerator generates an EM field around the luminal network of thepatient to be navigated, for example, airways, gastrointestinal tract,or a circulatory pathway. The steerable channel is inserted through theworking channel of the bronchoscope and tracked in the EM field via theEM sensor.

Prior to the start of an EM navigation-guided bronchoscopy procedure, avirtual, 3D bronchial model can be obtained for the patient's specificairway structure, for example, from a preoperative CT chest scan. Usingthe model and an EM navigation-guided bronchoscopy system, physicianscan navigate to a desired location within the lung to biopsy lesions,stage lymph nodes, insert markers to guide radiotherapy or guidebrachytherapy catheters. For example, a registration can be performed atthe beginning of a procedure to generate a mapping between the EMcoordinate system and the model coordinate system. Thus, as theinstrument is tracked during bronchoscopy, the instrument's position inthe model coordinate system becomes nominally known based on positiondata from the EM sensor.

FIG. 16A illustrates an example operating environment 100 implementingone or more aspects of the disclosed navigation systems and techniques.The operating environment 100 includes patient 101, a platform 102supporting the patient 101, a surgical or medical robotic system 110guiding movement of an instrument 115, command center 105 forcontrolling operations of the robotic system 110, EM controller 135, EMfield generator 120, and EM sensors 125, 130. FIG. 16A also illustratesan outline of a region of a luminal network 140 within the patient 101,shown in more detail in FIG. 16B.

The system 110 can include one or more robotic arms for positioning andguiding movement of instrument 115 through the luminal network 140 ofthe patient 101. Command center 105 can be communicatively coupled tothe robotic system 110 for receiving position data and/or providingcontrol signals from a user. As used herein, “communicatively coupled”refers to any wired and/or wireless data transfer mediums, including butnot limited to a wireless wide area network (WWAN) (e.g., one or morecellular networks), a wireless local area network (WLAN) (e.g.,configured for one or more standards, such as the IEEE 802.11 (Wi-Fi)),Bluetooth, data transfer cables, and/or the like. The robotic system 110can be any of the systems described above with respect to FIGS. 1-15 .An embodiment of the system 110 is discussed in more detail with respectto FIG. 16C, and the command center 105 is discussed in more detail withrespect to FIG. 17 .

The instrument 115 may be a tubular and flexible surgical instrumentthat is inserted into the anatomy of a patient to capture images of theanatomy (e.g., body tissue) and provide a working channel for insertionof other medical instruments to a target tissue site. As describedabove, the instrument 115 can be a procedure-specific endoscope, forexample a bronchoscope, gastroscope, or ureteroscope, or may be alaparoscope or vascular steerable catheter. The instrument 115 caninclude one or more imaging devices (e.g., cameras or other types ofoptical sensors) at its distal end. The imaging devices may include oneor more optical components such as an optical fiber, fiber array,photosensitive substrate, and/or lens(es). The optical components movealong with the tip of the instrument 115 such that movement of the tipof the instrument 115 results in corresponding changes to the field ofview of the images captured by the imaging devices. The distal end ofthe instrument 115 can be provided with one or more EM sensors 125 fortracking the position of the distal end within an EM field generatedaround the luminal network 140. The distal end of the instrument 115 isfurther described with reference to FIG. 18 below.

EM controller 135 can control EM field generator 120 to produce avarying EM field. The EM field can be time-varying and/or spatiallyvarying, depending upon the embodiment. The EM field generator 120 canbe an EM field generating board in some embodiments. Some embodiments ofthe disclosed patient navigation systems can use an EM field generatorboard positioned between the patient and the platform 102 supporting thepatient, and the EM field generator board can incorporate a thin barrierthat minimizes any tracking distortions caused by conductive or magneticmaterials located below it. In other embodiments, an EM field generatorboard can be mounted on a robotic arm, for example, similar to thoseshown in the robotic system 110, which can offer flexible setup optionsaround the patient.

FIG. 16B illustrates an example luminal network 140 that can benavigated in the operating environment 100 of FIG. 16A. The luminalnetwork 140 includes the branched structure of the airways 150 of thepatient 101, the trachea 154 leading to the main carina 156 (typicallythe first bifurcation encountered during bronchoscopy navigation), and anodule (or lesion) 155 that can be accessed as described herein fordiagnosis and/or treatment. As illustrated, the nodule 155 is located atthe periphery of the airways 150. The instrument 115 may comprise asheath 141 having a first diameter and thus the distal end of the sheath141 may not able to be positioned through the smaller-diameter airwaysaround the nodule 155. Accordingly, a scope 145 extends from the workingchannel of the instrument 115 and across the remaining distance to thenodule 155. The scope 145 may have a lumen through which instruments,for example, biopsy needles, cytology brushes, and/or tissue samplingforceps, can be passed to the target tissue site of nodule 155. In suchimplementations, both the distal end of the sheath 141 and the distalend of the scope 145 can be provided with EM sensors for tracking theirrespective positions within the airways 150.

In some embodiments, a 2D display of the 3D luminal network model asdescribed herein, or a cross-section of a 3D model, can resemble FIG.16B. Estimated position information can be overlaid onto such arepresentation.

FIG. 16C illustrates an example robotic arm 175 of the robotic system110 for guiding instrument movement in through the luminal network 140of FIG. 16B. The robotic arm 175 can include robotic arms 12, 39described above in some embodiments, and is coupled to base 180, whichcan include a cart base 15, column 37 of patient platform 38, or aceiling-based mount in various embodiments. As described above, therobotic arm 175 includes multiple arm segments 170 coupled at joints165, which provides the robotic arm 175 multiple degrees of freedom.

The robotic arm 175 may be coupled to an instrument manipulator 190, forexample instrument manipulator 62 described above, e.g., using amechanism changer interface (MCI) 160. The instrument manipulator 190can be removed and replaced with a different type of instrumentmanipulator, for example, a first type of instrument manipulatorconfigured to manipulate an endoscope or a second type of instrumentmanipulator configured to manipulate a laparoscope. The MCI 160 includesconnectors to transfer pneumatic pressure, electrical power, electricalsignals, and optical signals from the robotic arm 175 to the instrumentdriver 190. The MCI 160 can be a set screw or base plate connector. Theinstrument manipulator 190 manipulates instruments, for example, theinstrument 115 using techniques including direct drive, harmonic drive,geared drives, belts and pulleys, magnetic drives, and the like. The MCI160 is interchangeable based on the type of instrument manipulator 190and can be customized for a certain type of surgical procedure. Therobotic 175 arm can include a joint level torque sensing and a wrist ata distal end.

Robotic arm 175 of the robotic system 110 can manipulate the instrument115 using tendons as described above to deflect the tip of theinstrument 115. The instrument 115 may exhibit nonlinear behavior inresponse to forces applied by the elongate movement members. Thenonlinear behavior may be based on stiffness and compressibility of theinstrument 115, as well as variability in slack or stiffness betweendifferent elongate movement members.

The base 180 can be positioned such that the robotic arm 175 has accessto perform or assist with a surgical procedure on a patient, while auser such as a physician may control the robotic system 110 from thecomfort of the command console. The base 180 can be communicativelycoupled to the command console 105 shown in FIG. 16A.

The base 180 can include a source of power 182, pneumatic pressure 186,and control and sensor electronics 184—including components such as acentral processing unit, data bus, control circuitry, and memory—andrelated actuators such as motors to move the robotic arm 175. Theelectronics 184 can implement the navigation control techniquesdescribed herein. The electronics 184 in the base 180 may also processand transmit control signals communicated from the command console. Insome embodiments, the base 180 includes wheels 188 to transport therobotic system 110 and wheel locks/brakes (not shown) for the wheels188. Mobility of the robotic system 110 helps accommodate spaceconstraints in a surgical operating room as well as facilitateappropriate positioning and movement of surgical equipment. Further, themobility allows the robotic arm 175 to be configured such that therobotic arm 175 does not interfere with the patient, physician,anesthesiologist, or any other equipment. During procedures, a user maycontrol the robotic arm 175 using control devices, for example, thecommand console.

FIG. 17 illustrates an example command console 200 that can be used, forexample, as the command console 105 in the example operating environment100. The command console 200 may include a console base 201, one or moredisplays 202 (e.g., monitors), and one or more control modules (e.g., akeyboard 203 and joystick 204). In some embodiments, one or more of thecommand console 200 functionality may be integrated into a base 180 ofthe robotic system 110 or another system communicatively coupled to therobotic system 110. A user 205, e.g., a physician, remotely controls therobotic system 110 from an ergonomic position using the command console200.

The console base 201 may include a central processing unit, a memoryunit, a data bus, and associated data communication ports that areresponsible for interpreting and processing signals such as cameraimagery and tracking sensor data, e.g., from the instrument 115 shown inFIGS. 16A-16C. In some embodiments, both the console base 201 and thebase 180 perform signal processing for load-balancing. The console base201 may also process commands and instructions provided by the user 205through the control modules 203 and 204. In addition to the keyboard 203and joystick 204 shown in FIG. 17 , the control modules may includeother devices, for example, computer mice, trackpads, trackballs,control pads, controllers such as handheld remote controllers, andsensors (e.g., motion sensors or cameras) that capture hand gestures andfinger gestures. A controller can include a set of user inputs (e.g.,buttons, joysticks, directional pads, etc.) mapped or linked to anoperation of the instrument (e.g., articulation, driving, waterirrigation, etc.).

The displays 202 may include electronic monitors (e.g., LCD displays,LED displays, touch-sensitive displays), virtual reality viewingdevices, e.g., goggles or glasses, and/or other display devices. In someembodiments, the display modules 202 are integrated with the controlmodules, for example, as a tablet device with a touchscreen. In someembodiments, one of the displays 202 can display a 3D model of thepatient's luminal network and virtual navigation information (e.g., avirtual representation of the end of the endoscope within the modelbased on EM sensor position) while the other of the displays 202 candisplay image information received from the camera or another sensingdevice at the end of the instrument 115. In some implementations, theuser 205 can both view data and input commands to the system 110 usingthe integrated displays 202 and control modules. The displays 202 candisplay 2D renderings of 3D images and/or 3D images using a stereoscopicdevice, e.g., a visor or goggles. The 3D images provide an “endo view”(i.e., endoscopic view), which is a computer 3D model illustrating theanatomy of a patient. The “endo view” provides a virtual environment ofthe patient's interior and an expected location of an instrument 115inside the patient. A user 205 compares the “endo view” model to actualimages captured by a camera to help mentally orient and confirm that theinstrument 115 is in the correct—or approximately correct—locationwithin the patient. The “endo view” provides information aboutanatomical structures, e.g., the shape of airways, circulatory vessels,or an intestine or colon of the patient, around the distal end of theinstrument 115. The display modules 202 can simultaneously display the3D model and CT scans of the anatomy the around distal end of theinstrument 115. Further, the display modules 202 may overlay the alreadydetermined navigation paths of the instrument 115 on the 3D model and CTscans.

In some embodiments, a model of the instrument 115 is displayed with the3D models to help indicate a status of a surgical procedure. Forexample, the CT scans identify a lesion in the anatomy where a biopsymay be necessary. During operation, the display modules 202 may show areference image captured by the instrument 115 corresponding to thecurrent location of the instrument 115. The display modules 202 mayautomatically display different views of the model of the instrument 115depending on user settings and a particular surgical procedure. Forexample, the display modules 202 show an overhead fluoroscopic view ofthe instrument 115 during a navigation step as the instrument 115approaches an operative region of a patient.

FIG. 18 illustrates the distal end 300 of an example instrument havingimaging and EM sensing capabilities as described herein, for example,the instrument 115 of FIGS. 16A-16C. In FIG. 18 , the distal end 300 ofthe instrument includes an imaging device 315, illumination sources 310,and ends of EM sensor coils 305. The distal end 300 further includes anopening to a working channel 320 of the endoscope through which surgicalinstruments, such as biopsy needles, cytology brushes, and forceps, maybe inserted along the endoscope shaft, allowing access to the area nearthe endoscope tip.

EM coils 305 located on the distal end 300 may be used with an EMtracking system to detect the position and orientation of the distal end300 of the endoscope while it is disposed within an anatomical system.In some embodiments, the coils 305 may be angled to provide sensitivityto EM fields along different axes, giving the disclosed navigationalsystems the ability to measure a full 6 degrees of freedom: threepositional and three angular. In other embodiments, only a single coilmay be disposed on or within the distal end 300 with its axis orientedalong the endoscope shaft of the instrument. Due to the rotationalsymmetry of such a system, it is insensitive to roll about its axis, soonly 5 degrees of freedom may be detected in such an implementation.

B. Techniques for Location Sensor Registration.

As discussed above, location sensors may be used to track the locationof a portion of an instrument (e.g., the distal end of the instrument)with respect to a model of an anatomy of a patient through which theinstrument is driven during a medical procedure. It is to be appreciatedthat the model may be generated based on pre-operative measurements andthe location sensor may function based on an independent coordinatesystem. In order to accurately determine the location of the instrumentusing the location sensors, the location sensor coordinate system isregistered to the model coordinate system, which provides atransformation that can be applied to measurements from the locationsensors to arrive at corresponding positions within the model coordinatesystem. FIG. 17 illustrates an example command console 200 that can beused, for example, as the command console 105 in the example operatingenvironment 100. The command console 200 may include a console base 201,one or more display 202 (e.g., monitors), and one or more controlmodules (e.g., a keyboard 203 and joystick 204). In some embodiments,one or more of the command console 200 functionality may be integratedinto a base 180 of the robotic system 110 or another systemcommunicatively coupled to the robotic system 110. A user 205, e.g., aphysician, remotely controls the robotic system 110 from an ergonomicposition using the command console 200.

In certain implementations, the location sensor coordinate system can beregistered to the model coordinate system based on location sensor datataken while the instrument is driven within the patient's anatomy. Theamount and type of data required for registering the location sensorcoordinate system to the coordinate system of the model of the anatomymay depend on the shape of a given anatomy. For example, one techniquefor registering a location sensor coordinate system to a modelcoordinate system involves maintaining a history of the data receivedfrom the location sensor(s) and matching the shape formed by thelocation data history to the candidate paths along which the instrumentcan travel based on the model of the anatomy. This technique may be moresuccessful in finding a registration between the location sensorcoordinate system and the model coordinate system for anatomies whichhave a certain amount of asymmetry.

FIG. 19 illustrates an example luminal network in which location sensorregistration can be performed in accordance with aspects of thisdisclosure. In the embodiment of FIG. 19 , the illustrated luminalnetwork 400 corresponds to a patient's airway and includes afirst-generation airway 405 (e.g., a trachea) which branches into twosecond-generation airways 415 and 420 (e.g., primary bronchi) at a maincarina 410. Also illustrated is a target 425 (e.g., a lesion or nodulewithin the luminal network 400) to which the system may drive theinstrument during a medical procedure. A target path 430 provides aplanned route along which the instrument can be driven to reach thetarget 425. Depending on the embodiment, the system may automaticallygenerate the target path 425 based on the pre-operatively scanned modelof the luminal network 400 and the location of the target 425. In otherembodiments, the target path 425 may be selected by a user duringpre-operative planning. The system may display an illustration of thetarget path 430 with respect to the model on a display to provide theuser with an indication of the direction in which to drive theinstrument to reach the target 425. In certain embodiments, the targetpath 430 may include only a direct path to the target 425 which does nottraverse the same portion of a luminal network more than once (i.e.,traversing the target path 425 does not involve advancing down a segmentof the luminal network and retracting the instrument back along the samesegment).

As should be appreciated the airways defined by the second-generationbranches 415 and 420 may not be symmetrical, but instead have differentlengths and form different angles with the first-generation airway 405.In certain registration techniques in accordance with this disclosure,so called contra-lateral registration, leverage this asymmetry betweenthe branches 415 and 420 to improve instrument registration. Embodimentscan leverage the asymmetry by driving the instrument along acontra-lateral route 435, which may include driving the instrument intothe second-generation airway 415 that is contra-lateral to the airway onthe target path 430, retract back to the first-generation airway 405,and then drive to the second-generation airway on the path 430. As isdiscussed below, embodiments may additionally include features tofacilitate the contra-lateral registration, such as automaticallydetecting the contra-lateral branch 415 and automatically determiningwhen the distance traversed by the instrument along the contra-lateralbranch 415 is sufficient.

To better explain the use of the contra-lateral route 435, the route ortrace defined by the data output from the location sensors during theregistration process (including the contra-lateral route 435) can becompared to the various shapes defined by the model of the luminalnetwork 400. Due to the asymmetrical shape formed by the luminal network400, the route defined by the location sensor data during theregistration process may uniquely correspond to a single portion of themodel of the luminal network 400, namely, the shape defined by thefirst-generation airway 405 and each of the second-generation airways415 and 420. Thus, the registration between the location sensorcoordinate system and the model coordinate system may be defined basedon a transformation between the route or trace defined by the locationsensor data (e.g., the contra-lateral route 435) during the registrationprocess and the shape defined by the first-generation airway 405 andeach of the second-generation airways 415 and 420.

Although FIG. 19 provides an example of a patient's airway as anembodiment of a luminal network, aspects of this disclosure may alsoapply to registration of location sensors used to navigate other luminalnetworks, and in particular, luminal networks which are at leastpartially asymmetric. For example, aspects of this disclosure may beapplied to a gastro-intestinal network, a urinary tract, a vascularnetwork, etc. Thus, aspects of this disclosure relate to theregistration of location sensors based on location data received whiledriving an instrument along at least a portion of an asymmetricalroute—within a luminal network.

FIG. 20A is a flowchart illustrating an example method operable by asurgical robotic system, or component(s) thereof, for contra-laterallyregistering a location sensor coordinate system in accordance withaspects of this disclosure. It is to be appreciated that the steps ofmethod 500 illustrated in FIG. 20A may be performed by a processor of asurgical robotic system. For convenience, the method 500 is described asperformed by the processor of the system. When relevant to thedescription of the various steps of the method 500, reference will bemade to the luminal network 400 illustrated in FIG. 19 to describe oneembodiment of the method 500 below.

The processor may be included as a part of a system, including aninstrument having a set of one or more location sensors. The set oflocation sensors may be configured to generate location data indicativeof a position of the set of location sensors in a location sensorcoordinate system. The location sensors may be located at or near adistal end of the instrument (e.g., see FIG. 18 ), and thus, thelocation data may be indicative of the location of the distal end of theinstrument. The system may further include a set of instrumentmanipulators configured to control movement of the distal end of theinstrument and at least one computer-readable memory in communicationwith the processor and having stored thereon a model of a luminalnetwork of a patient. The model may include a target within a modelcoordinate system and a path to the target. The memory may further havestored thereon computer-executable instructions to cause the set ofprocessors to perform the method 500.

The method 500 begins at block 501. At block 505, the processor providesa first set of commands to the set of instrument manipulators to drivethe instrument along a first branch (e.g., a contra-lateral branch 415)of the luminal network. In some embodiments, the first set of commandmay be generated based on user input received from a set of one or moreuser input devices. Thus, the processor may cause user instructions tobe provided to a user which include instructions to follow the set ofmovements associated with the registration process (e.g., to drive theinstrument along a first portion of the contra-lateral registrationroute 435). The system may then receive the user input corresponding tothe user instructions and generate the first set of command for movementof the instrument along the first branch. As illustrated in FIG. 19 ,first branch 415 is located outside of the target path 430 to the target430. Thus, the first set of commands may cause the instrumentmanipulators to drive the instrument along the first portion of thecontra-lateral registration route 435 down the contra-lateral branch415.

At block 510, the processor tracks a set of one or more registrationparameters during the driving of the instrument along the first branch.The registration parameters may be any data that can be tracked by thesystem and used to determine whether sufficient data has been collectedby the system to perform registration between the location sensorcoordinate system and the model coordinate system. At block 515, theprocessor determines that the set of registration parameters satisfy aregistration criterion. The registration parameters satisfying theregistration criterion may be indicative of the instrument travelling asufficient distance along the contra-lateral branch 415 and theregistration process can continue with the instrument being retractedback to the target path 430. A more detail embodiment for tracking theregistration parameters and determining whether the registrationparameters satisfy the registration criterion is provided below inconnection with FIG. 20B.

At block 520, the processor provides a second set of commands to the setof instrument manipulators to return the instrument back to the targetpath 430 and to drive the instrument along a second branch (e.g., thelateral branch 420). As illustrated in FIG. 19 , the branch 420 islocated along the target path 430 to the target 425. The processor maydrive the instrument along the remainder of the contra-lateralregistration route 435, continuing down the lateral branch 420.

At block 525, the processor determines a registration between thelocation sensor coordinate system and the model coordinate system basedon the location data received from the set of location sensors duringthe driving of the instrument along the first branch and the secondbranch (e.g., along the contra-lateral registration route 435). Byconfirming that the registration parameters satisfy the registrationcriterion in block 515 prior to providing the commands to retract theinstrument back to the lateral branch 420, the processor can ensure thatsufficient location data is collected to determine the registration. Themethod 500 ends at block 530.

In certain embodiments, the registration between the location sensorcoordinate system and the model coordinate system may be further basedon the first set of commands referenced in step 505 and the second setof commands from step 520. That is, the first and second sets ofcommands may be robot data which provided to the instrumentmanipulator(s) to control the movement of the instrument. Since thefirst and second sets of commands are used to control the movement ofthe instrument, the processor may be able to determine the location ofthe instrument when moved based on the first and second sets ofcommands. Thus, the processor may be able to determine the location ofthe distal end of the instrument with respect to the model based on therobot data used to drive the instrument. As an example, if the distalend of the instrument is located at or near the carina (see the carina410 illustrated in FIG. 19 ) and positioned to drive down the firstbranch (e.g., the contra-lateral branch 415), after providing aninsertion command to the instrument, the processor may determine thatthe distal end of the instrument has been inserted into the first branchby the amount instructed in the insertion command.

The processor may further be configured to generate the first and secondsets of commands, provided to the instrument manipulator, based on userinput received from a set of one or more user input devices. Thus, thedriving of the instrument may be performed manually based on user inputreceived by the system.

As discussed above, the registration may include a transformation thatcan map data from the location sensor coordinate system to the modelcoordinate system. The transformation may include a translation and/or arotation that can be applied to location sensor data. To aid indetermining the registration which correctly maps data from the locationsensor coordinate system to the model coordinate system, the processormay identify a known location in each of the two coordinate systemswhich can be used as an anchor between the location sensor coordinatesystem and the model coordinate system. With reference to FIG. 19 , thecarina 410 can be automatically identified from the model of the luminalnetwork and the user can easily navigate the instrument to the carina410 and provide feedback to the processor indicative of the location ofthe carina 410.

In certain embodiments, the system may also generate guidinginstructions to determine an anchor point at a known location in each ofthe location sensor and model coordinate systems. The guidinginstructions may include instructions to the user to drive the distalend of the instrument to touch the carina 410 and then retract theinstrument after touching the carina 410. Based on user input, theprocessor may provide commands to drive the instrument to the carina 410and retract the instrument after reaching the carina 410. Thus, byidentifying the location of the instrument just prior to the retraction,the processor can determine that the identified location within thelocation sensor coordinate system corresponds to the location of thecarina 410. The location of the carina 410 in each of the two coordinatesystems can then be used as once piece of data to determine thetransformation mapping the location sensor coordinate system to themodel coordinate system.

In another example embodiment, rather than requiring the user toindicate the location of the carina 410 by retracting the instrument,the processor may determine the location of the instrument with respectto the model using a camera included on the distal end of theinstrument. The user may use images captured by the camera and providedto the display to navigate through the luminal network. In oneembodiment, images obtained by the camera may be displayed to the userin real-time. The processor may be configured to determine a position ofthe distal end of the instrument based on an analysis of an imagereceived from the camera. Any image processing technique that candetermine the features of the interior of the luminal network may beused to determine the position of the distal end of the instrument withrespect to the model. The processor may further determine that thedistal end of the distal end of the instrument is within a thresholddistance from the first location (e.g., the carina 410) based ondetermined position of the distal end of the instrument.

FIG. 20B is a flowchart illustrating an example method operable by asurgical robotic system, or component(s) thereof, for determiningwhether sufficient location data has been received to facilitatecontra-lateral registration in accordance with aspects of thisdisclosure. It is to be appreciated that the steps of method 550illustrated in FIG. 20A may be performed by a processor of a surgicalrobotic system. For convenience, the method 550 is described asperformed by the processor of the system. The steps of method 550 may beperformed as an implementation of block(s) 510 and 515 of FIG. 20A.

The method 550 begins at block 551. At block 555, the processor receivesraw location data and state data. As used herein “raw location data” mayrefer to location data indicative of a location within the locationsensor coordinate system. Thus, “raw location data” may be location datathat is representative of a location within the instrument coordinateframe rather than the model coordinate frame. Prior to performing theregistration process and determining a registration between the locationsensor coordinate system and the model coordinate system, the processorcannot map the location sensor data to the model coordinate system.Thus, it will be appreciated that the location data received prior tothe completion of the registration process is unregistered or rawlocation data.

The state data may refer to data produced by the processor which isindicative of the location of the instrument within the model. Forexample, the localization system 90 illustrated in FIG. 15 may be usedto produce location data 96 (also referred to as state data), which canbe used in the methods 500 and 550. The state data may include depthinformation, such as the current depth of the instrument in a givensegment or an insertion depth within the anatomical model. The statedata may also include an orientation of the distal end of the instrumentin the model coordinate frame. In certain embodiments, the processor mayreceive the raw location data and state data throughout the registrationprocess 500 illustrated in FIG. 20A.

At block 560, the processor may store the location data and state datacollected during a registration process, such as the registrationprocess performed via the method 500. The registration process mayinclude a choreographed set of movements of the instrument which may berelated to the shape of the luminal network. The set of movements mayalso be based on a defined target path 430 to a target 425 within themodel. The registration process may involve providing a first set ofcommands to the set of instrument manipulators to drive the instrumentalong a first branch of the luminal network, where the first branch ison the contra-lateral branch 415 and, thus, outside of the target path430 to the target 425. The registration process may also involveproviding commands to bring the instrument back to and continue alongthe target path 430 to the target site 425. The choreographed set ofmovements may include the set(s) of commands required to drive thedistal end of the instrument along the path defined by thecontra-lateral registration route 435. The processor may track a set ofone or more registration parameters during the driving of the instrumentalong the first branch, such as depth information.

At block 565, the processor may determine whether sufficient locationsensor data has been collected as part of the contra-lateral phase ofthe registration process based on the registration parameters beingtracked. In one embodiment, the processor may use registrationparameters such as depth information (e.g., an insertion depth of theinstrument) to determine whether the instrument has been driven asufficient distance along the contra-lateral branch 415 of thecontra-lateral route 435. In certain embodiments, after one registrationcriterion is satisfied, the processor may provide a second set ofcommands to the set of instrument manipulators to return the instrumentback to the target path 430 and to drive the instrument towards thetarget site along a second branch. As the instrument continues along thetarget site, the processor may continue tracking the instrument locationdata and state data for the registration process.

By determining whether the instrument has been driven a sufficientdistance along the contra-lateral branch 415, the system may be able toreduce the amount of input required from the user, thereby reducing thechances of user-error. For example, certain registration processes mayrequire the user to drive to a plurality of defined locations andprovide an input to the system indicating that the instrument has beendriven to the defined locations. By eliminating this type of requireduser input, aspects of this disclosure can improve the ease of theregistration process and reduce potential sources of user error.

At block 570, the processor may register the location coordinate systemto the model coordinate system using the location data and state datatracked during the registration process (e.g., location data and statedata tracked along the contra-lateral route 435 and the target path430). As discussed above, this may include matching the shape of thepath taken by the instrument as tracked using the location sensors tothe shapes of the luminal network defined by the skeletal structure ofthe model. In certain embodiments, the shape of the model having thelowest difference from the tracked path is selected and used todetermine a registration between the location sensor coordinate systemand the model coordinate system. It is to be appreciated that becausethe tracked path includes the contra-lateral branch 415, embodiments mayreduce the likelihood that the tracked path matches to other candidatepaths in the model. The method 550 ends at block 575.

In determining the registration, the processor may be further configuredto match the shapes defined by histories of the location sensor data androbot data. Thus, in certain implementations, the processor may beconfigured to generate a set of location data points representative ofthe location of the distal end of the instrument with respect to thelocation coordinate system while driving the instrument along thecontra-lateral registration route. The processor may further generate aset of model points representative of the location of the distal end ofthe instrument with respect to the model coordinate system while drivingthe instrument along the contra-lateral registration route. Theprocessor may generate the model points based on the history of robotdata and the model. The two sets of points may be used by the processorto determine the registration between the location coordinate system andthe model coordinate system is based on determining a registration whichmaps the set of location data points in the location coordinate systemto the second set of model points in the model coordinate system.

FIG. 21 is a diagram illustrating location data with respect to a modelof a luminal network in accordance with aspects of this disclosure. Inthe example of FIG. 21 , the diagram 600 includes model 602 of apre-operative scan of the luminal network, which may also include askeleton 605 defined by the midpoints along each of the airways definedby the model 602. In particular, the skeleton 605 includes a series ofsegments, each located at the midpoint of corresponding lumens in theluminal network. Also illustrated is ground truth data 610 representingthe actual or true location of the distal end of the instrument during acontra-lateral registration process relative to the anatomy. The groundtruth data 610 shown in FIG. 21 may have been generated by a testingtool that is not normally used during a procedure to highlight theaccuracy of the contra-lateral registration process. In the illustratedexample, a target 625 may be located on the left side of the figure.Accordingly, during a registration procedure, the instrument may bedriven from the first-generation airway 630 into the contra-lateralsecond-generation airway 635. Thereafter, the instrument may beretracted back into the first-generation airway 630 and advanced intothe lateral second-generation airway 640 located along a path to thetarget 625.

The system may also track the state data 615 representing the locationof the instrument along the skeleton of the model 605. As discuss above,the processor may determine the state data based on data received fromone or more different sources of data indicative of the location of thedistal end of the instrument (e.g., via the localization module 95 ofFIG. 15 ). Once sufficient data is received during the registrationprocess, a registration transformation can be applied to the rawlocation data to generate registered location data 620. As shown in FIG.21 , the registered location data 620 may closely track the ground truthdata 610. After the location data has been registered, the processor mayuse the registered location data 620 as an input in determining thestate data 615.

FIG. 22 is a diagram illustrating an example of registration of locationdata without preforming a contra-lateral registration process inaccordance with aspects of this disclosure. In this example, when acontra-lateral registration process is not performed (e.g., theinstrument is not driven down a contra-lateral branch) the raw locationdata 705 may substantially match two different candidate paths 710 and715 within the model. That is, each of the two candidate paths 710 and715 may have a similar shape such that a rotation and/or translation ofthe raw location data 705 may substantially match both paths 710 and715. However, since the two paths 710 and 715 diverge, selecting theincorrect path 715 for registration may cause the location data toprovide an incorrect indication of the location of the instrument whendriven past the divergence between the two paths 710 and 715. Incontrast, by performing a contra-lateral registration process inaccordance with aspects of this disclosure, the incorrect candidateregistration path 715 can be removed from the set of candidateregistrations since a registration based on the incorrect candidateregistration path 715 would not provide a match in shape along thecontra-lateral route taken by the instrument (see, e.g., FIG. 21 ).

As discussed above, the contra-lateral registration procedure mayprovide a more accurate and more robust registration when the firstbranch and the second branch are asymmetrical (e.g., thesecond-generational segments). Thus, in certain embodiments, a processormay select an asymmetrical branching of the luminal network for thecontra-lateral registration procedure. This selection of the locationwithin the luminal network may also reduce the number of possiblesolutions to the matching between the location data and the model,leading to a more robust registration procedure. In the bronchoscopyexample, driving the instrument into a contra-lateral branch beforeproceeding along the path to the target may provide sufficient rawlocation data to facilitate the registration of the location sensors tothe model coordinate system. Accordingly, in certain embodiments, thefirst branch is located on a contra-lateral side of the luminal networkwith respect to the target.

C. Location Sensor Registration Planning.

Aspects of this disclosure also relate to pre-operative planning whichmay involve determining instructions and/or criterion related to alocation sensor registration procedure. FIG. 23 is a flowchartillustrating an example method operable by a surgical robotic system, orcomponent(s) thereof, for pre-operative planning in accordance withaspects of this disclosure. The procedure 800 for pre-operative planningmay be operable by a surgical robotic system, or component(s) thereof,for pre-operative planning in accordance with aspects of thisdisclosure. For example, aspects of the method 800 for pre-operativeplanning may be performed by a command console, such as the commandconsole 200 illustrated in FIG. 17 or may be performed by a processor(or a set of processors) of a surgical robotic system, which may beincluded as part of the command console. For convenience, the method forpre-operative planning is described as performed by the processor of thesystem. In certain embodiments, the system may also include at least onecomputer-readable memory in communication with the set of processors andhaving stored thereon a model of a luminal network of a patient. Themodel comprises a target within a model coordinate system and a path tothe target. The memory may also store computer-executable instructionsto cause the set of processors to perform the method 800.

The method 800 begins at block 801. At block 905, the processor providesinstructions to display the luminal network via a display device. Inparticular, the processor may provide instructions to display theluminal network via a display device. This may involve, for example, theprocessor retrieving a model of the luminal network from the memory anddisplaying the model to be viewed by a user. The display of the modelmay involve displaying, for example, the skeleton and/or a more detailedsegmented image generated based on preoperative scans of the luminalnetwork (as shown in FIGS. 19, 21 and 22 ).

At block 810, the processor receives an indication of a location of atarget within the model coordinate system. For example, the processormay receive an indication from a user, via a user input device, of atarget portion of the model at which at least a portion of a medicalprocedure is to be performed. The target may be, for example, a desiredlocation within the lung to biopsy lesions, stage lymph nodes, insertmarkers to guide radiotherapy or guide brachytherapy catheters. In otherembodiments, the system can automatically detect or otherwise determinethe target location 425 based on detecting features in the preoperativescan that are indicative of a tumor.

At block 815, the processor identifies a first branch (e.g., a branchlocated on a contra-lateral side of the luminal network, such as thecontra-lateral branch 415 of FIG. 19 ) and a second branch (a branchlocated on the lateral side of the luminal network such as lateralbranch 420 of FIG. 19 ) in the luminal network. Since the identifiedfirst and second branches are respectively located on the contra-lateraland lateral sides of the luminal network with respect to the location ofthe target, the first branch may be located outside of the path to thetarget and the second branch may be located along the path to thetarget.

In certain embodiments, based on the model and the selected target, theprocessor may automatically identify certain segments of the model whichmay be traversed by the instrument to aid in registration of thelocation sensors. This may include the processor identifying the firstbranch as a branch located on a contra-lateral side of the luminalnetwork and the second branch as a branch located on a lateral side ofthe luminal network. In certain embodiments, the first and secondbranches may be second-generation branches of the luminal network, suchas branches 415 and 420 illustrated in FIG. 19 . The processor mayfurther be configured to determine that the shape formed by the firstand second branches is sufficiently unique within the luminal networksuch that, when the instrument is driven along a contra-lateralregistration route defined by the second-generation branches, no othershape within the model will match the path taken by the instrumentduring the contra-lateral registration process. This determination maybe performed by comparing the shape of the first and second brancheswith other possible shapes in the model to determine whether thereexists any possible conflicts in shapes.

As discussed above, certain registration processes may require the userto drive the instrument to a plurality of defined locations within theluminal network and provide an indication to the system when theinstrument is located at the defined locations. This technique may alsorequire the user to identify the defined locations during apre-operative planning stage. However, since the processor mayautomatically identify a contra-lateral route which can be used for theregistration process, the necessary steps for the user during thepre-operative planning stage can be reduced.

At block 820, the processor generates a set of guiding instructions fordriving the distal end of the instrument along the first branch, back tothe path from the first branch, and along the second branch. Thus, theset of instructions may define a contra-lateral registration route, suchas the contra-lateral registration route 435 of FIG. 19 . The guidinginstructions may be stored in memory to be provided to a user during themedical procedure. During the medical procedure, location data receivedfrom the set of one or more locations sensors during the driving of theinstrument according to the instructions may facilitate a registrationbetween the a location coordinate system of the location data and themodel coordinate system. The registration may include at least one of atranslation and a rotation between the location coordinate system andthe model coordinate system. At block 825, the processor determines aregistration criterion for one or more registration parameters trackedduring the driving of the instrument along the first branch. The method800 ends at block 830.

The registration criterion may relate to the amount of location datarequired for registration of the location sensor coordinate system tothe model coordinate system. For example, the criterion may specify arequired distance of travel for the instrument along the contra-lateralbranch before the instrument can be returned back to the path from thefirst branch. The registration criterion may also depend on the specificshape of the patient's anatomy. For example, airways for some patientsmay have a larger discrepancy between the shapes and angles formedbetween the first and second branches than for other patients. When thedifferences between the first and second branches are more pronounced,it may not be necessary for the instrument to travel as far down thefirst branch to receive sufficient data for registration. In otherembodiments, the registration criterion may be set based on a thresholddetermined to provide sufficient location data for registration for themajority of patients for the particular procedure which will beperformed.

The registration parameters may include an insertion depth of theinstrument into the contra-lateral branch. In this embodiment, the setof registration parameters satisfy the registration criterion inresponse to the insertion depth into the first branch being greater thana threshold insertion depth. For example, the registration criterion mayinclude instructions to drive the instrument along at least 50% of thecontra-lateral branch before returning to the first-generation branch onthe path. The specific value may be different depending on theparticular anatomy involved in the medical procedure and/or based on ananalysis of the variation in the shapes of the anatomy in the generalpopulation.

Depending on the particular medical procedure, the processor may alsodetermine whether the first branch and the second branch areasymmetrical. The processor may identify the first and second branchesin response to determining that the first and second branches areasymmetrical. As discussed above, the registration process may be moreaccurate for asymmetrical paths and/or asymmetrically shaped luminalnetworks. Thus, the processor may select a bifurcation in the luminalnetwork having an asymmetrical shape for the location at which theregistration process is to be performed. In certain embodiments, such asfor an airway, one branch at which the registration process can beperformed is the branch from the trachea into the main bronchi. Thus,the processor may identify the first branch is further in response todetermining that the first branch is located on a contra-lateral side ofthe luminal network with respect to the target.

In certain embodiments, the set of instructions include instructions todrive the instrument to a first location within the luminal network. Thefirst location may be a location identifiable by the user during themedical procedure which can provide a known location within each of thelocation sensor coordinate system and the model coordinate system. Forexample, during a bronchoscopy procedure, the first location maycorrespond to the patient's carina. The carina may be identified withinthe model based on its location at the branch between the main bronchiand the user may be able to drive to the carina prior to theregistration of the location data. In this embodiment, the first andsecond branches may correspond to main bronchi of the patient. Theregistration between the location sensor coordinate system and the modelcoordinate system may be further based on location data received fromthe set of location sensors while the distal end of the instrument iswithin a threshold distance from the first location. By using the firstlocation as a known point of reference between the location coordinatesystem and the model coordinate system, the number of permutations forthe registration can be limited. Additionally, the user instructions mayinclude an instruction to retract the instrument after touching thecarina. This retraction may be interpreted as an indication of theposition of the carina, which can be used as the first location duringthe registration procedure.

3. Implementing Systems and Terminology

Implementations disclosed herein provide systems, methods andapparatuses for the registration of location sensors to a modelcoordinate system.

It should be noted that the terms “couple,” “coupling,” “coupled” orother variations of the word couple as used herein may indicate eitheran indirect connection or a direct connection. For example, if a firstcomponent is “coupled” to a second component, the first component may beeither indirectly connected to the second component via anothercomponent or directly connected to the second component.

The functions described herein may be stored as one or more instructionson a processor-readable or computer-readable medium. The term“computer-readable medium” refers to any available medium that can beaccessed by a computer or processor. By way of example, and notlimitation, such a medium may comprise random access memory (RAM),read-only memory (ROM), electrically erasable programmable read-onlymemory (EEPROM), flash memory, compact disc read-only memory (CD-ROM) orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium that can be used to store desiredprogram code in the form of instructions or data structures and that canbe accessed by a computer. It should be noted that a computer-readablemedium may be tangible and non-transitory. As used herein, the term“code” may refer to software, instructions, code or data that is/areexecutable by a computing device or processor.

The methods disclosed herein comprise one or more steps or actions forachieving the described method. The method steps and/or actions may beinterchanged with one another without departing from the scope of theclaims. In other words, unless a specific order of steps or actions isrequired for proper operation of the method that is being described, theorder and/or use of specific steps and/or actions may be modifiedwithout departing from the scope of the claims.

As used herein, the term “plurality” denotes two or more. For example, aplurality of components indicates two or more components. The term“determining” encompasses a wide variety of actions and, therefore,“determining” can include calculating, computing, processing, deriving,investigating, looking up (e.g., looking up in a table, a database oranother data structure), ascertaining and the like. Also, “determining”can include receiving (e.g., receiving information), accessing (e.g.,accessing data in a memory) and the like. Also, “determining” caninclude resolving, selecting, choosing, establishing and the like.

The phrase “based on” does not mean “based only on,” unless expresslyspecified otherwise. In other words, the phrase “based on” describesboth “based only on” and “based at least on.”

The previous description of the disclosed implementations is provided toenable any person skilled in the art to make or use the presentinvention. Various modifications to these implementations will bereadily apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other implementations without departingfrom the scope of the invention. For example, it will be appreciatedthat one of ordinary skill in the art will be able to employ a numbercorresponding alternative and equivalent structural details, such asequivalent ways of fastening, mounting, coupling, or engaging toolcomponents, equivalent mechanisms for producing particular actuationmotions, and equivalent mechanisms for delivering electrical energy.Thus, the present invention is not intended to be limited to theimplementations shown herein but is to be accorded the widest scopeconsistent with the principles and novel features disclosed herein.

What is claimed is:
 1. A system to register a set of one or morelocation sensors of an instrument, comprising: a set of one or moreprocessors of a computer system; and at least one computer-readablememory of the computer system in communication with the set of one ormore processors and having stored thereon: a model of a luminal networkof a patient, the model comprising a target within a model coordinatesystem, a path to the target, a first branch, and a second branch,wherein the path to the target goes through the second branch but notthe first branch, the memory further having stored thereoncomputer-executable instructions to cause the set of one or moreprocessors to: provide a first set of commands to a display device todrive the instrument along the first branch of the luminal network,track a set of one or more registration parameters during the driving ofthe instrument along the first branch, determine that the set of one ormore registration parameters satisfies a registration criterion,responsive to the determination that the set of one or more registrationparameters satisfies the registration criterion, provide a second set ofcommands to the display device to return the instrument back to the pathand to drive the instrument along the second branch, and determine aregistration between a location sensor coordinate system and the modelcoordinate system based on location data received from the set of one ormore location sensors during the driving of the instrument along thefirst branch and the second branch.
 2. The system of claim 1, whereinthe registration comprises at least one of a translation or a rotationbetween the location sensor coordinate system and the model coordinatesystem.
 3. The system of claim 1, wherein the first branch and thesecond branch are asymmetrical.
 4. The system of claim 1, wherein thefirst branch is located on a contra-lateral side of the luminal networkwith respect to the target.
 5. The system of claim 1, thecomputer-executable instructions further cause the set of one or moreprocessors to: provide a third set of commands to the display device todrive the instrument to an anchor point in the luminal network, whereinthe registration between the location sensor coordinate system and themodel coordinate system is based on the location data received from theset of one or more location sensors while a distal end of the instrumentis within a threshold distance from the anchor point.
 6. The system ofclaim 5, wherein: the anchor point corresponds to a carina of thepatient, and the first branch and the second branch correspond to mainbronchi of the patient.
 7. The system of claim 1, wherein: the set ofone or more registration parameters comprises an insertion depth of theinstrument into the first branch.
 8. The system of claim 7, wherein: theset of one or more registration parameters satisfy the registrationcriterion in response to the insertion depth into the first branch beinggreater than a threshold insertion depth.
 9. The system of claim 1,wherein the set of one or more location sensors comprises a set ofelectromagnetic (EM) sensors located at a distal end of the instrument.10. The system of claim 1, wherein the set of one or more locationsensors comprises a set of shape sensing fibers located at a distal endof the instrument.
 11. A non-transitory computer readable storage mediumhaving stored thereon instructions that, when executed, cause at leastone computing device to: provide a first set of commands to a displaydevice to drive an instrument along a first branch of a luminal network,the instrument comprising a set of one or more location sensors, the setof one or more location sensors configured to generate location dataindicative of a position of the set of one or more location sensors in alocation sensor coordinate system, a memory having stored thereon: (i) amodel of the luminal network of a patient, the model comprising a targetwithin a model coordinate system and a path to the target and (ii) aregistration route comprising the first branch of the luminal networkoutside the path to the target and a second branch of the luminalnetwork that is a part of the path to the target; track a set of one ormore registration parameters during the driving of the instrument alongthe first branch in accordance with the registration route; determinethat the set of one or more registration parameters satisfies aregistration criterion; responsive to the determination that the set ofone or more registration parameters satisfies the registrationcriterion, provide a second set of commands to the display device toreturn the instrument back to the path and to drive the instrument alongthe second branch in accordance with the registration route; anddetermine a registration between the location sensor coordinate systemand the model coordinate system based on the location data received fromthe set of one or more location sensors during the driving of theinstrument along the first branch and the second branch.
 12. Thenon-transitory computer readable storage medium of claim 11, wherein theregistration comprises at least one of a translation or a rotationbetween the location sensor coordinate system and the model coordinatesystem.
 13. The non-transitory computer readable storage medium of claim11, wherein the first branch and the second branch are asymmetrical. 14.The non-transitory computer readable storage medium of claim 11, whereinthe first branch is located on a contra-lateral side of the luminalnetwork with respect to the target.
 15. The non-transitory computerreadable storage medium of claim 11, wherein: the set of one or moreregistration parameters comprises an insertion depth of the instrumentinto the first branch.
 16. The non-transitory computer readable storagemedium of claim 15, wherein: the set of one or more registrationparameters satisfy the registration criterion in response to theinsertion depth into the first branch being greater than a thresholdinsertion depth.
 17. A method of registering a set of one or morelocation sensors, comprising: providing a first set of commands to adisplay device to drive an instrument along a first branch of a luminalnetwork, the instrument comprising the set of one or more locationsensors, the set of one or more location sensors configured to generatelocation data indicative of a position of the set of one or morelocation sensors in a location sensor coordinate system, a memory havingstored thereon: (i) a model of a luminal network of a patient, the modelcomprising a target within a model coordinate system and a path to thetarget and (ii) a registration route comprising the first branch of theluminal network outside the path to the target and a second branch ofthe luminal network that is a part of the path to the target; tracking aset of one or more registration parameters during the driving of theinstrument along the first branch in accordance with the registrationroute; determining that the set of one or more registration parameterssatisfies a registration criterion; responsive to determining that theset of one or more registration parameters satisfies the registrationcriterion, providing a second set of commands to the display device toreturn the instrument back to the path and to drive the instrument alongthe second branch in accordance with the registration route; anddetermining a registration between the location sensor coordinate systemand the model coordinate system based on the location data received fromthe set of one or more location sensors during the driving of theinstrument along the first branch and the second branch.
 18. The methodof claim 17, wherein the registration comprises at least one of atranslation or a rotation between the location sensor coordinate systemand the model coordinate system.
 19. The method of claim 17, wherein thefirst branch and the second branch are asymmetrical.
 20. The method ofclaim 17, further comprising selecting the first branch in response todetermining that the first branch is located on a contra-lateral side ofthe luminal network with respect to the target.